https://store.steampowered.com/app/1474790/BooomSlang/
Trapped in a deadly gameshow, in order to survive, you will need to fight mutated creatures, use crazy weapons & abilities, collect treasures, avoid sinister traps and obtain insane power-ups in this Top-Down, Twin-Stick Shooter with a wacky FMV/Low-CGI style and multiple Single+Multiplayer modes.

INSTRUCTION FOR ACTIVATION:

1. You must download and install Steam http://steampowered.com/download/SteamInstall.msi
2. Log in to your account or register a new one.
3. Go to the "My Games" section and select "Activate via Steam ..." and enter the key received after payment.
4. After activation, the game will appear in the list of games (Library) and you can download it