Here is the full list of all 23 Hundred Chances - there are The Fortress achievements.
You died 50 times
You killed the Green Bomber
You reached Level 05
You died 30 times
You killed 50 enemies
You killed the Slime
You died 10 times
You killed the Orange
You killed the Blue
Firts Death
You killed the Red Bomber
You killed the Witch
You killed the Tank
You killed the Star
You defeated the Bear
You defeated the Cyclop
You defeated the Minotaur
You beat the Alien
You cleared Level 27
You reached Level 15
You reached Level 29
You cleared the Game in 30 minutes or less
You cleared the Game