Here is the full list of all 15 Gachi Dash achievements.
Beat the "Jail" level
Beat the "Shop" level
Beat the second level
Beat the first level
Be defeated by hitting a bottle for the first time.
Beat the "Hospital" level
Beat the "Gym" level
Beat the "Banya" level
Beat all game
Die 100 times on the level
Die 1000 times summary
Get 69 points in Endless Mode
Unlock Doomer
Unlock fun
Unlock Real Man