Here is the full list of all 31 Ultimate Chicken Horse achievements. It takes around 15-20 hours to unlock all of the achievements on Windows.
Unlock all outfits
Place 1000 traps
Score 50 comeback points
Get 50 coins
Enter sudden death 20 times
Play 100 games
Get 10 post-mortem points
Teleport 50 times
Kill someone with a hockey puck shooter 100 times
Win without any special points
Score 100 solo points
Unlock all levels
Kill someone with an arrow 100 times
Die 50 times in a black hole
Unlock all characters
Place 200 traps
Play online with a local friend
Play 50 games online
Die with the coin 10 times
Wall jump 1000 times
Play 30 games
Unlock a character
Fall into the void 100 times
Play 10 games
Play 10 games online
Kill people with traps 100 times
Unlock an outfit
Die on barbed wire 10 times
Unlock a level
Attach two blocks together with glue
Glue four blocks together