Onion Force (Steam key/Region free).

http://store.steampowered.com/app/434980/
All the kings are dead… except one...

Onion Force is a hybrid Tower Defense/Action Adventure game with 30 levels of butt-puckering mayhem! Use cunning and strategy to strengthen your team chosen from a diverse cast of characters, and hang on to your seat as you try to save the last king from his doom!

Make intelligent choices, collect gold, onions, and equipment. Build towers that will be most effective for the threat at hand. Decimate evil through an array of terrain, weather conditions, destructible environments and utter chaos to find the source of this nonsense.

Game features:

- Stand-out cartoon graphics and stellar special effects & animation

- 3 playable heroes, each with their own unique abilities

- 6 fully fleshed out locations with 30 expansive levels

- Thousands of pieces of equipment to collect and equip

- 8 different towers types with 5 different power levels each

- Collectable onions to trade for a wide variety of power-ups

- Adjustable game speed.