You're looking at a mixed bag of achievements here.

SINGLE PLAYER
Aside from the 1000 achievement, you won't need to worry about being too good at the game, so take your time and slowly learn it as best as you can.

MULTIPLAYER
Unless specified, you can get all VS Achievements with a friend but it has to be online, Local doesn't count.

Special thanks to:
CammyTopGear1997 for the 'Speedy Treeles' and 'Dark Horse' achievements
BeccyVengeance for the 'War in Heaven' and 'Multitree' achievements

Score 1001 or chop 150000 trees

Simple as it sounds and as an added bonus, this guide also covers the 'score x to unlock y' achievements

TIPS:
-To clear every branch it requires two chops. So when you're furiously chopping around make sure to note that and you'll instinctively start doing it
-From 0-100, take your time. Once you passed 101 start picking up pace and speed up every hundred. Once you've cleared 500 it is time to start button smashing without stopping
-This will take a few attempts (This took me 50 tries) but anything is possible with enough training

Simple as it sounds. Die with a score of 180 to a branch. This might take a few attempts depending on how lucky you are to get a branch around the 180 mark but it should be fairly easy (Also you must die by a branch, not let time run out)

TIPS
-Breeze through 0-100 but after 101 take your time so you don't accidently cross 180
-If there is a space and a branch on the other side, your score will still be counted if you chopped it
-If there is a branch directly opposite you, moving into it won't increase your score

Score more than 200 three times in a row

An easy achievement. just score more than 200 three times in a row. That means once you have selected a character and completed your first game, you can't exit it. (Also it says MORE than 200 so don't die on 200)

TIPS
-Make sure you select a character you like and won't want to change
-Doesn't matter how you die after you score 200
-Don't die on 200
-Must be done in a row, meaning you can't score 200, die to 94 and then score 200

*Must be done online, no local play

Speedy Treeles
Win three rounds in a row by being much faster than opponent

An easy achievement. Just be faster than the opponent 3 times in a row without dying once. To make it even more easier just ask a friend to help you

TIPS
-You have to win 3 times IN A ROW. If you die once then you have to start again
-You also have to be faster than your opponent meaning they can't die by a branch
-You can do this achievement with a friend



Dark Horse
Beat 10 much stronger opponents in multiplayer

Same as the Speedy Treeles one except you don't have to win 10 times in a row or be faster than them. Again you can just get a friend to do nothing and keep beating them

TIPS
-You don't have to win 10 times in a row so you can die
-Doesn't matter how the other person dies
-You can do this achievement with a friend

War in Heaven
Fight in multiplayer with devils and angles only

Play a game using only the Angel and/or Devil characters (You don't have to win, just play a game)

TIPS
-For Step 1, just take your time. If you have go at a steady pace, you should easily clear 150 or more (Remember to use Santa or else it'll be pointless)
-For Step 2, you have to 22 points in order to beat the other person in speed. So when you start have the other person score 21 and then let them remain idle and beat them (They can't die by a branch)
-I earned this achievement in Online Multi 2 Players with a friend. I'm not sure if it works in Offline Multi or with Online Multi 2+
-You can do this achievement with a friend

Special thanks to BeccyVengeance for helping me with this achievement

Multitree
Fight 10 times in multiplayer mode

Play a game with 2+ people 10 times. This can be done Local or online and you don't have to win, you just need to play 10 games

-You don't need to win, you just need to play 10 games
-You need to play 10 games, not 10 rounds
-The fastest way to do this is to literally have the other person (Or yourself) chop on one side very fast because their is always a branch within the first 5 chops

Special thanks to BeccyVengeance for helping me with this achievement

*Must be done online, no local play. Also 4+ Mode works as well
*I reccommend doing this with friends to make it A LOT EASIER as Online Players won't be willing to let you win

Kicker
Defeat 25 people by being much faster in 4 players mode

You need to be faster than AT LEAST 1 PLAYER 25 times. These wins build up overtime and each player counts

TIPS
-OPTIONAL Get 1 friend to remain idle so that you can beat them
-You need to be 22 Points ahead to kill the other players


Chainsaw
Win 33 4 Players matches
Simple, just win 33 4 players matches. This doesn't have to be in a row or constant, you can take breaks in between or build them up. All you have to do is win so it doesn't matter how the others die. Make sure you don't have 3 people in a 4 player game or else it won't count (But if someone leaves during a 4 player match it will count)

TIPS
-OPTIONAL Get 3 friends to help you as Online Players won't be willing to let you win

Special thanks to BeccyVengeance, Cammy_Top_Gear and A!Hat for help with these achievements

And that is about it

-FingerRocks