Bug Free, at last i didn't find one.
Nice Mouse Movement Game, very solid, Kenney Assets always nice to see.
Leaderboard would be cool and then its a solid nice small Game.
Challenges of the Gameplay could be improved, different Weapons, Powerups, there are a bunch of Options for the Game and additional features.
From the Theme, mhh No Way Out okay, there's no way out of the Square your playing in. but besides that im not convinced about it, just personal Opinion.
good work!