A nice WIP.
Player sprite is adorable, especially with the hat animation.
Collisions still need some work

But your main problem is that you're already out of map room.
This can be addressed by using compression PX9? (https://www.lexaloffle.com/bbs/?tid=34058 )
and/or alternate map system. Picomap ? ( https://www.lexaloffle.com/bbs/?tid=42848 )
and/or multiple chained carts.

Thank you very much for your words and advice! :D
The PX9 compression is impressive... I want to keep the map quite small since I want to keep it simple for my kids to complete it. It is my first PICO-8 project and I am really enjoying the process!
I uploaded an update correcting the collision. :)
Thank you!!