Move with WASD, shoot with mouse. You've heard of Sharpshooter... but have you heard of... Shapeshooter?! This is an io game! Multiplayer shooting action! Feature list: Auto game joining! Target detector! Target timeouts! Auto game leaving! This was very hard to make.
Note: You can't see projectiles. Just click on people to damage them. But if people are moving, then it will be hard to hit them so get ready for some fun. Thanks to @griffpatch for pretty much inventing cloud multiplayer. I based it off of his concept, but DID NOT watch a video or anything about it, I just winged it, and it turned out pretty well.