Use the space bar in the first phase to swallow Dark Matters projectiles. When Dark Matter starts attacking you, that's when you press the space bar to unload all your stored projectiles back at him! Arrow keys to move around, duh. I'm pretty sure that's it :p
Yo, my fellow scratchers. It's been so long since ive been on here, I barely know how to work anything anymore aha. But I ended up making this, i think it turned out alright :D enjoy!