As a long time indie game dev I must say that it turned out pretty good.What I like about your game is the weapon system because its smooth and fits to the game as well as the enemy ai which is pretty good as well.a few things i noticed were that the legs were buggy sometimes but besides that i like the concept a lot.if you add multiplayer and some type of story /game destination and a hook at the start of the game to make the player hyped.you should make it replayable so the player can come back with more and new enemies for example at a certain level.but your game could definetly get popular.Sorry for my bad english its because im from germany