I really like the idea! I think the level designs could use some work, like in the first level I didn't really need to shoot the enemies since I could just walk through. The second level was better though since there were points where I actually did need a reason to shoot the enemies to progress. I would like to see the mechanics of the game being utilized better in the levels :D
Also the main menu was really big for me for some reason, but I was able to click on the play button so it's fine for me.
Good job! I think you have a good foundation here for a bigger game.
I'd really appreciate it if you rated my game too!