Great little game! I found the art style to be simple and refreshing. Always good to see an "invaders" game.
While I might just have skill issues, I did find the game to be incredibly difficult. I tried a few different strategies several times, but nothing got me past the first level. I shot some of them many times, but they didn't seem to die. Eventually, I realized that they just had a ton of health.
Another thing, you probably will not get recognized as much as you should for the wide selection enemies. Most people would make two enemies and maybe a boss (for a game jam), but you created many unique obstacles for the player.
If you wouldn't mind playing the game I worked on, Ricochet by woutan
Great work!