Alright thanks for the advice! As for getting stuck, before the fight with the star starts the burger wasn't yet there, so I was able to walk into it which caused me to be stuck there after the whole sequence was done. I ended up needing to simply redo the start sequence of the game and not stand there. I made a screenshot of it after it was over.
With the advice I was able to get past the encounter and was able to finish the rest of the demo. The rest of the game was all cool and fun, so I have nothing to say about that! I think the main problem I had with the mushroom gang is that (at least to me) it felt like the type of encounter that's meant to say "you're not actually meant to go here yet", mostly due to how much collective health the gang has. I think simply lowering the amount of damage you need to deal to beat the encounter would probably help for this, but I don't think it *necessarily* needs fixing, so keeping it how it is would be fine too. What you've made so far is already really great, and I'll make sure to keep following its development!