This is a great first step into game making imo. It looks sleek, and it works, which is more than can be said for most peoples' first attempts.
Still, I'd say it barely qualifies as a game. It's a very simple shooter game, and it gets really repetitive really fast. I got to level 3 and realized it was all just the same grind. Kill enemies, get ammo, get super weapon for a short time, repeat. Maybe add some sort of level system that's separated from this arcade style system you've got now? Or switching out the "ammo" system for a currency system to be used on various upgrades like bullet damage, reload time, variety of enemies etc