Great job on the game! Platforms being one time use and having to complete the same level with the previous touched platforms gone is quite interesting.
The larger gravity flipping levels were strange to navigate, and I didn't really like the part in the last level where you would have to wait for the swinging platform. Having to wait for automatic platforms to go and come back is always a bit frustrating, though I could just go to the far right and use gravity to get my way over there.
It's hard to tell which parts were from the Corgi Engine already and what were done by you, so I'll just say what I thought overall. The character was really cute, nice and stretchy, the dash was impactful, the controls were responsive and the UI was very, very polished, like the loading screen, level selects and menus.
I liked the text boxes, as they gave hints and tips as we went, even between stages and not just levels, I didn't really like the limited lives system, it didn't seem like it was neccessary to be booted back to the level selection after 3 deaths.
The level design was very well done as it needed thought for multiple paths for each stage after accounting for missing platforms, being able to take out the level box limits, like the ceiling so you can walk on top is fun creative and out of the box thinking. Each level as we went on was a good gradual introduction to the game's mechanics. The rope swings at the last level only being catchable by the tips was a little frustrating, but not too bad to get used to or get around them.