It’s an amazing and well-made game! I beat the boss (by just grabbing the book 😂). There’s a lot of charm in the storytelling, the intro actually gave me a nostalgic Ghosts n’ Goblins feel. There’s also lots of awesome mechanics and details especially in the wall jumping. I see you’ve implemented coyote time too, which is great. The art and animations seems really polished, good job on that!
I experienced a few minor bugs. I saw a comment about sound problems, and I experienced it too. At 2-3, all sound and music suddenly stopped after the monster took the book. It did get restored once 3-1 started though. If this bug is not reproducible on your side, and you suspect it’s a browser issue, perhaps you can make a downloadable Windows build. An intermittent bug is still a bug nonetheless, so I hope you’ll be able to find out the problem eventually. There are also some collision problems for some of the enemies where it only detects the sides, which confused me at first because sometimes it killed me and sometimes it didn’t; so even if this was the intention, it still needs a little adjusting. Another strange thing is when climbing the chain, sometimes I only have to press jump once to get off, but most of the time I have to press it twice. Occasionally, even if I jumped off the chain, my character magically grabs on the same chain again, so I have to press jump 4 times in total to get off.
Overall, it’s an awesome platformer with good game design and I love the controls. There’s a lot of potential in this game, so I definitely would love to see it developed further in the future. All the best!