Thanks! Glad you enjoyed it!
- I'll have to investigate the issue with the screen going black, it's not an issue I'm aware of. If I find the glitch and push an update, I'll let you know.
- Cores getting flung away like that is actually a game mechanic, it's possible to deliberately fling them back at enemies and blow them up. I worry that the mechanic might be too confusing and I'm tempted to remove it for the sequel.
- I've had this mentioned before, and I've tried resolving it by making the bullets flash, while the cores don't. There's still probably more I can do to differentiate them, and again, it's something I'll look into for the sequel.