Boxhead is the interesting shooting game which is made by Sean Cooper. In the game, you will fight against your enemies by shooting at them. You can use a lot of modern weapons such as shot guns, rockets, grenades, etc. Interestingly, there are more rooms and two different modes such as cooperative and death match one for you to freely discover.
I just have an advice before you start playing the game. You should wall up one side so that there is only way for your enemies to approach you: go straight! In this case, you will have more chances to defeat them.