The project looks like it has the potential to be a lot of fun. You have to remember though, not everyone is going to reply to your thread, even if they are interested in the project.
As BackendFreak mentioned, you'll need to do a bit of polishing yet, but also think about building fun scenarios with the mechanics you've created. It's fun to shoot things, but not if it's just enemies trickling in from the sides.
Give the player the tools to have fun with. Items that attract or repel enemies, piles of numerous enemies on screen (think something like Dark creatures from the Rayman games), combination weapons and traps that you have to set off (like dousing a pit in gas, luring enemies inside and lighting them on fire), defensive items to get you out of trouble (maybe a launchpad item, or a bulldozer type shield), interesting environments that complement the weapon mechanics (I see mostly wide open levels in your gifs).
There is so much you could do you the framework you've got so far.