I was able to play for some time before game freezed and i can point out few things. I like the art and gameplay, but i think you should keep single pixel size for everything in future. Overall good job!
Sorry to hear you encountered that bug. we havent seen that problem yet. Any idea on what could of caused it? and the pixel sizes are the same for the sprites. Thats why some enemies are smaller and bigger as theyre a different pixel size but set to 16x16 in Unity. thanks for the review!