Here is the full list of all 15 Rage Wars achievements.
Unlock Rocket launcher in store
Unlock chainsaw in store
Kill last boss
Go in rage mode 200 times
Do 100 killstreak chain 10 times
Unlock laser in store
Unlock game rage faces in store
Collect 5000 potatoes in game
Complete World 2
Unlock flame thrower in store
Complete World 1
Kill total of 1000 zombies in game
Unlock rifle in store
Do 50 killstreaks in game
Unlock Shotgun in store