Pretty fun! I got to wave 16 with a score of 467. Sadly I died shortly after finding the hex boss. I think it would be a bit more engaging if different enemy types are more interspersed each wave, because most waves seem to end with a big collection of blue guys which is a little boring 

The main mechanic is a cool idea that fits with the theme. As previously stated, it was not very clear that enemies in their smallest form could be collected (maybe a color change could do the job). Also, I don't know if it is a bug but sometimes when I clicked on an enemy, it didn't hit him. The overall style is simple but nice and easy to read, the shader is a nice addition. I feel the waves are perhaps too numerous, or the difference in difficulty between them doesn't increase enough so the game feels a bit repetitive.

Cute little game, I really loved the shader you used to create the retro feel. I think the main thing that was confusing for me was that it was not immediately clear that the enemies, when in their smallest form, are supposed to be collected rather than avoided. It took me until about wave 5 to realise that haha.

Cool and well-executed idea. I love the retro style of the game.