https://store.steampowered.com/app/1169060/Shield_Shock/

Shield Shock is a 2D Platform Fighter Game all about blocking! Use your shield to block enemy projectiles and release mighty attacks right back! This 4-Player Party Fighting Game will have you playing alongside friends to defeat the onslaught of Blockers or face off against each-other to see who is the finest Wielder of Shields!

Activation Instructions:

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