Here is the full list of all 26 Time Knight VS. Zombies achievements.
Finish the game in easy mode
Finish the game in normal mode
Finish the game in normal+ mode
Finish the game in hard mode
Finish the game in hard+ mode
Kill 100 enemies
Kill 500 enemies
Kill 1000 enemies
Buy all weapons at least once
Finish the game
Go through all levels through the Grand Tour
Gather more than 10,000 coins
Finish the Grand Tour stage on yolo mode
Beat the Statue
Beat the UFO
Beat the Mole
Beat the Plants
Unlock the normal+ mode
Unlock the hard+ mode
Get all achievements
Kill all 4 bosses
Die for the first time
Finish the first Stage on YOLO mode
Finish the second Stage on YOLO mode
Finish the third Stage on YOLO mode
Finish the fourth Stage on YOLO mode