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