I have played 3 runs of the mod so far.

First run was a Popularity build. I don't think I got the relics I needed to make it work perfectly and I took a few bad cards early on, but it felt like it was very well balanced otherwise.
Second run I focused playing on-beat. I got a consistent Home Run strat down, and got very late in the game, before dying to Nemesis.
Third run I replaced my relic which gave me the 5/4 time signature (So cool!), so I planned on using Countdown cards. I really couldn't get the blue rockets to pay out because I had a lot of relics that allowed me free cards and this character is really fun to play a lot of cards with. I ended up just using a tonne of repeat cards and getting a lot of strength to do big multi-hits. I made it to the heart fight with this build, but died due to a lack of block.

Overall, I feel that blocking is the hardest thing to do with this character. There are a lot of amazing options for getting extra energy and doing crazy high damage, but not a lot for negating incoming damage.
Excellent mod. The card art changing and the sound effects changing on the beat is such a brilliant touch.

id love for there to be a few more launch party cards, because i want the archetype to be larger, and because its one of my favorite RHF rhythm games.

@yessoan @SuperiorSeraph Thanks for playing! I'm glad you both tried out the (currently underpowered) countdown archetype. I'm experimenting to expand the countdown archetype without being too polarizing.

V0.1.3 contains a new card that can negate incoming damage and/or support the countdown archetype by removing multiple artifacts:

Love Lizards. 0 cost. Uncommon. Apply 1 Weak 2 times.

Not sure if this should go in bug reports instead, but: a combination of DJ School, Freepeat, and Double Up's power already in effect (and I think also Dead Branch) somehow allows me to create an infinite where a repeated card creates 0-cost clones of itself.

@SolarNougat. Double Up and Freepeat are a bit too strong together right now. Therefore, Double Up will be updated to "The first card without Ethereal you play each turn gains Repeat." to prevent repeating repeated cards. (Similar to the behavior of DJ School)

After playing some more, I agree with Yessoan's opinion that this character feels lacking in block options. Given that Countdown is also a part of the character's mechanics that doesn't feel fleshed out yet in terms of card variety, my idea would be to add more common and uncommon Countdown cards that allow it to be a defensively oriented mechanic compared to Popularity. Perhaps with powers like:

"Gain 1(2) Block whenever you play a card while a Countdown effect is active."
"Whenever you gain a Measure while a Countdown effect is active, draw 1 card."
"Whenever you play a card with Countdown, all enemies gain 1(2) Weak. Whenever a Countdown effect resolves, all enemies gain 1(2) Vulnerable."

These might sound unbalanced off the gate, but I consider this some idea pointers for how you might add more Countdown related powers.

Fillbots grants you free Beats up to 1 Measure per turn - but a second Fillbots buff doesn't grant a 2nd set of free Beats. I'm assuming this is to balance against a Measure archetype. Understandable if intended, though I regret picking the second card up! I assume if both Fillbots were upgraded, their block-granting effects would stack? I hope so.

I'd also like to sign onto Solarnougat and Yessoan's assessment of damage mitigation. Bit hard to keep damage down before a certain "tipping point", about mid Act 2.

@SolarNougat. Thanks for the suggestions, I especially like "Gain 1(2) Block whenever you play a card while a Countdown effect is active". Countdown effects typically want to be delayed. (PartyCracker can OTK when delayed and PreParty will have more effects to trigger) And this power promotes the usage of delaying cards like CoffeeBreak and TryAgain.

@M-Y-R-I-A-D, yes only the blocking parts of Fillbots stack. I feel like gaining multiple measures each turn is a bit too strong. But if you manage the end your turn on beat 1, an additional (upgraded) copy of Fillbots still functions like an upgraded Metallicize. (assuming a 4/4 time sig)

The character could use some X cost cards. If nothing else it gives a purpose to the Chemical X relic.

Just played several Rhythm Girl runs this week. Big fan of Rhythm Heaven and the cards you've got so far are fun to play, but I think the balance is off.
If you're still looking for ideas, then here's everything I got after a week. First, the synergies:

Heaven (seeing heaven, rhythm heaven, two-mode cards)
Bossa Nova is the character's best common, and then there's three other two-mode cards that are all good picks before you get any heaven (Screwbot and Crop Stomp at common, Wandering Samurai at uncommon).
Once you get some heaven, all of these cards get even better.
Bossa Nova is her best block, Screwbot is one of her only two weaks, and Crop Stomp is her only common draw. It seems like if I want to win, I've got to play heaven.

Countdown/Stalling (party cracker, alien knowledge, rat race, early bird, coffee break, try again)
I often pick an early Launch Party just because it's good damage for 1 energy. That kind of card is important for killing early elites but it's a bit of a gamble in Launch Party's case because the Nob gets angry and the Sentries block it, but it's fantastic against Lagavulin.
The other cards in this synergy are all uncommon, and three of them don't do much if you aren't already committed (Coffee Break, Try Again, Alien Knowledge). Rat Race and Early Bird can be interesting early picks, but they basically turn in to curses later if you don't get the right cards and start trying to play a normal 4-5 energy deck.
Party Cracker is powerful. The deck probably works better if you get 1-2 of them early, but I haven't got a run like that yet. Seems like the kind of deck that would have to hope that it draws the cards in the right order, though. That's probably what Packing Pests is for.

Measures/Popularity (a lot of cards)
This synergy has a lot of cards, so you usually have a little bit of it whether you're going for it or not.
The rare "payoff" cards (big flex, pose for the fans, square shoulders, growing popularity) are all pretty good, with Big Flex being the one that's worked best for me so far. Even with just two measures you're already getting an okay deal on Big Flex. Sometimes you get even more than that, and that's fantastic.
On the other side, there are about 6 common beat-generating cards, and the three I've found success with are Jab, See Saw and Fishing Rod. Those are the ones that deal damage to elites, so those are the ones that get early picks.
Rea--dy is pretty bad compared to Jab/See Saw. Upgrading it at least gets you the card you would have drawn if you didn't draw Rea--dy+... why did you spend a card pick and an upgrade on it if that's what you wanted? A single beat isn't really worth it.

Repeat (marching orders and... that's it, I guess)
All repeat cards are pretty good - Lumbearjack might actually be the worst one despite its rarity, it's best to just play it on 4 and forget about spending 1 energy for 6 damage.
Because they're all pretty good, I sometimes pick Marching Orders to go with them. Marching Orders is good for bosses, but you need to play about 3 repeats (or fish, or pitches) per fight to make it worth it in regular fights, which requires some commitment.


Secondly, the card set is small, so what's missing?
There's no 2+-cost at common and no X-cost at all.
It doesn't feel too strange because there's things like Air Rally to spend energy on, but it does hurt Snecko Eye and Chemical X.

Every repeat card deals damage except for the starter Into You, so they blend together a bit. There's no big repeat synergy card at rare (Big Flex is good with repeat cards, but it's also just good in most decks)

There's no cards that support the party cracker plan at common. Something like "get some damage/block, also the beat from this card adds to countdowns instead of reducing them", or whatever. There's only one common countdown card at all and it doesn't care about being delayed, which means that picking Launch Party doesn't help you get on-board with the rest of the synergies. As well as more countdown cards, maybe Launch Party should deal extra damage per delayed turn (+3? maybe even more?)

There's only three ways to draw cards - Crop Stomp, Monkey Business, Count In.
Tweezers and Rea--dy+ don't really count because they don't help you find your good cards, you just draw the card that you would have drawn if they weren't in the way.
Most characters get cards that do something and draw a card, but Rhythm Girl doesn't have any (except for heavened Crop Stomp, but that's more like an Offering/Adrenaline than a Shrug It Off or Sweeping Beam)

I agree with the people saying there isn't enough block, but I think there's the correct amount of block cards, it's just that most of them aren't good...
Common: Tall Screw is okay (Tall Screw+ is very bad - not worth the upgrade at all), Micro Row Swim is okay. Bossa Nova is, of course, good.
Uncommon: Flipper Roll is very very bad*. Alien Knowledge and Rat Race don't fit most decks. Plesiosaurus and Built to Scale are both good, but don't work with 0-1 measures. (that's fine, but it feels worse when they're the only good uncommon blocks)
Rare: Space bell is good, but it's rare, so it has rough competition.

*It's probably the worst card in the set, the only card I can't imagine ever picking.
Compare to leg sweep - Flipper Roll +2 is not as good as Leg Sweep +0
Compare to genetic algorithm - Usually you fight 2 or more times per camp, so you have to spend all of your campfires on Flipper Roll for it to keep up with the growth of a 1-cost card

I can't believe I spent all that effort writing that out and I forgot a couple of ways to draw cards in the set. Coffee Break and Try Again do it too, maybe I forgot some others.

So it's less that "there aren't a lot of ways to draw cards" and more that "The single-draw cards in the set are mostly uncommon and mostly do things with marginal or synergistic effects" (like beat generation and countdown delaying). There isn't a lot of cards I can pick that does something I always want and then replaces itself with a draw, which hurts the consistency of the character compared to the base game's characters.

Cards are insanely polarizing, it's impossible to win with only common cards, and remarkably hard to win with common and uncommon cards.

On the other hand you can have the whole deck be held up by a single Rare card, concept which i find too polarizing and somewhat unfun.
Many remarked how hard it is to get block, but i find it's just as hard to get dmg if not more, unless you get those very key cards.

All the dmg i managed to rack up was from popularity builds, and specific and hard to get countdown builds. Or the str multiplier of the power card that converts measure with str + usually bossa nova and jab
I feel like this character might become really fun to play, it just needs its level of power to be better distributed from the top to bottom.

Certain relics are also ridiculous, like the one that gives you the 0 cost repeated cards, absolutely bonkers

Also i'd love for basic cards to be just a tad differerent, maybe instead of the monkey strike a card that gives you beats somehow? The monkey card gets obsolete already half Act 1, and you wish for it to be removed by Act 2, just a glorified strike you won't play

BTW Coffee break is a little weird, after being played it looks like i gain unceasing top for the turn?

some thoughts:

lack of X cost cards- all vanilla characters have offensive X card(from 5 dmg ironclad to 9 dmg watcher), for rythm girl it should be gain X rythm, deal 5 damage X times, upgraded works with X+2

popularity build is a bit too strong, limit popularity activation to 2x per turn and cap measure at 20, but allow activation of "on full metrum" effects (like widget),
kill la kill mod has blood stacks that caps at 12, but gives further effects if you gain more

2/4 rythm seems interesting, but is near impossible to obtain, since you need to replace your starter relic on both bosses

rythm countersynergy: shortening metrum removes ability to effectively use cards with high on beat value

lack of high cost cards - usually makes confuse effect a gameover
hand full of cheap cards needed to gain measure becomes hand of high cost cards that loses all synergy and makes gaining measure near impossible
also lack of high cost cards that can benefit from confusion, that you also want in normal play

useless necronomicon: necronomicon plays first 2+ cost attack twice, giving players big power spike, but rythm girl lacks this feature:
pterodactyl can only be played if you have 2+ measure, which can be rather hard on turn 1 without proper build
sneaky spirit has special effect only on beat 4, making it regular attack otherwise
to counter that you could add some uncomon attack with effect on every beat(like bossa nova)

measure mechanic discourages the usage of high cost cards, I would suggest adding half of card cost as beat(in addition to regular 1 beat), and add tag to special cards to ignore these extra beats(pitch could instantly skip too many beats without this)

as someone previously mentioned common cards lack capability to win game on its own, some semistrong card should fill that gap, like attack that deals 3dmg + 2x measure, weak in early game, but scales pretty high with more energy and shorter metrum

lack of status effects: only 1 card is capable of inflicting effects other than ofensive countdowns (btw I like how screwbot working together with bossa)

buff for countdowns:
pre-party should also reset timers
add 1 attack card that deals low damage and inflicts damage countdown(similar to poisoned dagger), it would be great for fighting goblin nob without trigering his rage

rat race is underwhelming - getting barely 6 block for not obtaining measure is rather weak, considering how many low cost and repeat cards there are its hard to use it effectively(I would rather use 1 more bossa than skip measure), give it some effect that scales with measure

I like the pararel that double rea--dy+ does to double jumpkick - you can infinitely draw cards and deal damage (both need 1 more element to use - jumpkick needs vulnerable target, rea--dy+ needs popularity to make use of infinite measure, which I suggested nerfing above, or one of rare measure cards - shoulders, flex, pose)

speaking or rea--dy, I would suggest swapping base and upgraded effects
base rea--dy simply adds 2 beats, good for measure gaining, but not much else
if effects were swapped, it would give 1 beat and 1 card, giving it more use for building combos
NVM, if effects were swapped it could ruin decks that would rely on 1 beat skip if card was randomly upgraded in eventor with toxic egg relic

mandril strike is good starting card - deals "2x" more damage then regular strike, but thats all, once player direct deck into 1 of builds it becomes obsolete
other trademark starters can stay in deck and be useful whole game:
bash - 2vuln, neutralize - weak, eruption - wrath
while this card should be something that represents character, it should also be useful later in game, the on-beat effect is essence of rythm girl, but screwbot is far better at it.
I would suggest further buffing mandril somehow, like increasing base damage slightly, and adding special effect of player choice(2 vuln, 2 weak or 1 of both)

try again card is too punishing with removing all measure, make it halve it instead

alien knowledge is still too weak
should give 1 def for every countdown active(to make it stronger) when card is played on even beat(to not make it too strong)

some kind of relic that allows to play non-ethereal on-beat only cards regardless of beat, but with some negative effect, like losing 3HP per missing beat

There's not enough card manipulation or cards that let you build up an engine. The only energy generation is crop stomp, and crop stomp is also the main source of draw. However, you really need rhythm heaven or an upgrade to get benefit from them, because otherwise you are just trading energy for draw or draw for energy, and it's not strong enough to let you play more useful cards in one turn without rhythm heaven or upgrades. You are basically fully reliant on relics to let you do more stuff.

All the base characters have ways of generating energy and drawing cards, and can go infinite with a tightly honed deck. They also have other ways of manipulating the deck (Ironclad exhaust, Silent discard, Watcher scry. Defect has hologram at least.)