I like the monochromatic look a lot , the atmosphere, and a vertical shooter is always good in my boek ;)
Be careful about ennemies that are bullet sponges, simple ennemies should be just 'popcorn'?
Thanks for playing! I'm a big fan of those monochromatic looks in games, your game had a really good art style, where it reminded me of old crayon drawings I used to make as a kid, really nostalgic for me!