Awesome little game! :D I got a little bit of lag/slowdown when the bullet shooting enemies appeared (1-4?). I found with my own game turning on color mode in GBStudio (even if you're using no color options) improves the engines ability to cope with lots of sprites on screen :) just a tip!
Love the game and excited to see the full thing!
Thank you for playing! I've been working on addressing the lag/slowdown issue through various updates, but haven't completely eliminated it yet. While color mode does indeed improve comfort, I'm creating the game in monochrome mode because I want to play it on the DMG. I'll be releasing an update soon, so please check it out again!