Thank you for playing my game! For your notes, the main menu took 18 hours straight to code and was a nightmare. I wanted to include arrows keys but it became too complex. I should have accounted for them from the start and built around it, that was my lack of foresight.
You are not alone in not knowing that you can control the bullets. I should have been more clear on that, and it stems from the game changing direction. (You used to be able to only control Doki) and should have had more thought.
The idea was between the sponge texture and gamer knowledge that it was a play on bullet sponge. But you are right I should have added clearer indication, my apologies for the confusion.
It was explained about the buttons actually, though I could have done more this is true.
I did include a short tutorial into the dialog, but my code was too rough to implement anything more. Pictures for tutorials sounds marvelous though! Most people are visual learners, so I will keep this idea in mind, thank you so much!