Thanks for your feedback! You aim to the left or right depending on which direction you're moving. I was thinking of having some indicator that would show it but felt it was a bit difficult to do it nicely within the resolution limits.
About the ground collision. I didn't want to have the collision exactly on the ground as I didn't think it would feel "bubbley" enough(whatever that even means). The collision is actually below the ground tile and I made it so it will bounce you back if you go below it. Wanted to give the player a bigger area to move around in as well because of how the bubble-shot moves. I didn't know about that function though, so thanks for that! Might try that out next time I make something in PICO-8. :D