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