Thanks for the advice! It really helps for the future, so thanks.
- I would've liked to make that a bit clearer, with some better descriptions or even tooltips, but they definitely were ambiguous in the current game, so sorry about that.
- That would've been a nice idea, something like a second delay after opening, but I'm glad you figured out that you could hold down for autofiring in the end.
- Spawning enemies differently would've been a nice change too. FYI, they only spawn around the edges - although that's never explained in game at all, so it does just seem kind of random. Spawning them in a different area might've helped there.
Still, I'm glad you got through to the end, and I hope you had fun too! Thanks for the comment.