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