The fact that it says multiplayer in the discription is misleading, but they usually have to use the same discription, title, etc. on all sites regardless of the version. Needs Friction and badges!!!
Should add: Visible Score, Goal, Differrent weapons, enemy lives, player lives, different enemies,menu screen, high scores table, not just one-hit-kills, death count, upgrades, waves, a background, and better sprites. Not bad for a first attempt with no experience, keep working