Here is the full list of all 12 Bunny Reversi achievements.
Win 1 match against a friend
Lose 1 match against a friend
Win 1 match against AI
Win a match against AI at 3d level of difficulty
Win 10 times against a friend
Win 10 times against AI
Use all emotes
Swim 10 meters
Watch the game in the menu till the end
Jump from the water fall into the river
Lose 10 times against Bot
Unlock all the disk customizations