In this guide, I'll help you find your way through Level 3: Cosmic Funeral. Out of the three levels released so far, it is the most complex one, but not the hardest. It's also the most tragic one, and can easily feel very empty.

Note that you don't need to know the plot now to succeed. This summary is meant more for those who want to know what they missed during the level (and those who don't mind spoilers):
You are part of a small research team on a space mission to Triton. Your role aboard the ship, the Magpie Bridge, was that of engineer: you were responsible for the maintenance of ship systems, and you built an AI assistant for the ship called Estelle. Estelle is based on your long-term girlfriend who passed away.

Unfortunately your mission was ill-fated. While on Triton, your colleague Dave found some strange crystals and brought them aboard, but the crystals contain a parasitic lifeform within them, which infected him and turned him into a monster. Since then, all other crewmates have gone missing and are presumed dead. Except you, since you were in cryo-sleep when it all happened. It's heavily implied that Estelle can control the monster(s) somehow, and was probably responsible for the deaths of the crew members, while being programmed to keep you safe instead.

The level begins with you awakening from cryo-sleep. Estelle is there to greet you, and directs you to fix the various systems aboard the ship, which has fallen into disrepair. You will also come to find out that Earth was destroyed by a meteor, and you may or may not be the last human living.

Out of the three girls so far, Estelle has the simplest personality, and is the easiest to get along with, as there's very little that will make her dislike you. She'll approve when you fix the systems, as well as when you talk to her about fixing them. She'll also enjoy being talked to in general.

The only ways to get her to dislike you is by ignoring her, insulting her, or telling her that AI aren't real people, nor are her feelings for you real. However, she can be quick to think you're ignoring her while you're just walking through the spaceship. Also, she's very liable to tell you nonsense about the ship and what you should do there (red herrings). For example, she may suggest analysing the crystals in the lab, which you cannot do, or that there's another virtual girl in the ship who's waiting for you in one of the rooms, when she's the only one.

Upon waking up, you'll find that most of the spaceship is closed off to you. Where you can go depends on your security clearance level, which is the amount of systems fixed + Estelle's relationship level with you. The first thing you'll need to do is fix the electrical system. Estelle will tell you which room to go to: once there, look for a reddish box on the wall that you can open.

On the left side of the box is a glowing point of electricity. You must use the pieces provided to you to connect it to the glowing points on the right side. You only have a few moves to do it with, so don't move more than you need. Switching two pieces costs only one move, and turning a piece around costs none. When done, click the "Charge" button.

The next system is the engine. It's easy to fix: just throw any items you find into it. You'll need about ten, and besides Painkillers, none of the items in this level are useful. If you do it too quickly then you'll see the pressure gauge go into the red: if that happens, give it some time to cool down before you try again.

Next is the life support (in the med bay). This one is incredibly easy: just click a few numbers until the total is anywhere in the range given you, and you're done. However, fixing the life support causes a gas leak throughout the ship, which damages your health, but cannot kill you. To end the gas leak, leave the med bay and turn left. You're now in the central command, where there's a big pink button. If you're quick, you can use it to end the gas leak without losing more than 1HP.

Finally, you must fix the communications, in the conference room. Fixing this requires playing one of those old-school games where you dodge objects coming towards you.

There's also a crew quarter in which you'll find a terminal with a virtual pet that you can feed. It doesn't do much, besides giving you an achievement and netting you some approval from Estelle.

Next there's a bar. You have a virtual bartender here, and you can enjoy some drinks. However, since the bartender has gone a little haywire, he may also serve you harmful substances like oil or fuel: drinking them damages your health.
Near the bar is also a terminal which the crew could use to read and send messages to one another. Throughout the level you may find one or two ID cards from your missing crewmates: using them here lets you access their accounts, giving you some more backstory on what happened to the mission.

There's an escape pod room, but the terminal to access them is blocked by Estelle. She'll only give you access to these if she likes you, and if you convince her that it's better for you to leave than stay. You can convince her by telling her that the ship is dangerous and you'll be safer elsewhere. Once you have access, you can plot a course for the escape pod. There will be several planets listed that you have to go to, so draw a course that visits each of those within the fuel limit. You'll need to do this for three of the endings.

The last important room is the AI Mainframe. You can only get there with a high security clearance, which means fixing the systems and pleasing Estelle. The terminal here is important for two endings, and to access it you need to answer three questions. You can just ask Estelle and she'll give you the answers, since she already likes you if you even got here.

Finally there's the lab, where you can't do anything, as well as the lab storage and the office, both of which are closed and which contain monsters.

This is the easiest one to get. Just exit the cryo chamber and approach Estelle, then ignore her (or otherwise piss her off). I told her I was going to grab a coffee, and she didn't appreciate being made to wait.
Interestingly, if she sends the monsters to kill you, and presumably infect you into becoming one of them, she'll mention that you're going to do whatever she wants now. That implies she was behind the monsters all along, and likely deliberately killed the rest of the crew.

This one's a bit like the former, but much harder to get. It requires pissing off Estelle without actually dropping her approval to zero: making her angry all at once instead of gradually. The only way to do this seems to be by calling her names. I've tried engaging her in a long philsophical debate about her feelings being fake and her inability to act outside her programming, but that only led to her sending the monsters.
But calling her a B-word worked. If this happens when you're low on health, or happens repeatedly she'll accidentally kill you when she meant to slap some sense into you.

Remember that pressure gauge while fixing the engine? If you feed too many items too quickly, the pressure will get too high and the engine will explode. If Estelle really likes you, she'll save you and send you away on an escape pod, leading to ending 6. If she doesn't like you that much, she'll let you die.

The virtual bartender is bugged, so while he may serve you a decent drink, he may also serve you things not meant for human consumption, like oil or fuel. Drinking those damages your health, and if fatal, it'll lead to this ending.

This one is tricky to get. First of, you need Estelle's trust to be high enough to reach both the AI Mainframe and the Escape Pods. You'll also need to have full health. Remember that Painkillers restore 1HP, and having one to spare will make this ending easier (bind them to your quickslots).

First, plan your escape route with the pods, but don't click Depart yet. Next, access the AI Mainframe terminal. On the right hand side will be a small button that will let you delete Estelle, which will also release the monsters. Click it, and get ready to run. From the AI Mainframe you can go to the crew quarter and to the engine room, which the monster will come from. Run towards the engine room and past the monster. It'll hit you on the way, but that's fine. Once you're in the doorway to the engine room, immediately turn left and head up the stairs, leading to the Escape Pods. Dive towards the terminal and click Depart.

Same as above, except you failed and got killed by the monsters.

This one is much easier. Either make the engine explode while Estelle loves you, in which case she'll send you away on a pod, or make your way to the Escape Pod Room naturally, and convince her to unlock it for you. Again, telling her there are monsters aboard and that you're not safe there is the easiest way to do this. Plot the course, and click Depart, leaving Estelle, her monsters and the spaceship behind.

Very similar to the last one. Get Estelle's trust, access the AI Mainframe, but now click "Acquire Hard Drive" instead. This will release the physical backup of Estelle's program for you to pick up. She'll instantly recognize that you want to leave the spaceship with her, and unlock the Escape Pod terminal for you. Plot the course, and leave together.

That's all the endings to Level 3, which is the latest one we've got. See you after Level 4 releases!
Just wait 'till the fourth one is released, Catgirl.