Art style is suuuuper cute! The gameplay is interesting, and the idea of having more gems/power making you less agile is interesting, almost like a glass(or crystal) cannon!
A couple things I think you could look into.
The intro comic is actually well sectioned into "pages", so I think instead of having an eased scroll over the entire sequence, maybe one that pauses on each page section(for reading sections and not slowly peeking into them), with a quicker transition would be interesting (similar to a page turn).
The game asset art is of high quality, but I think they are just a little bit unreadable(as in the shapes and outlines) with the current browser resolution, even more so with the full screen resolution. (Maybe thicker outlines, or simplifying would help with that?)
I also died a lot, mostly due to me not keeping track of the crystal amount. Maybe you could have an audio/visual cue for when you're low on crystals.
Other than that, cool game, I loved the story and it was pretty funny! The characters were nicely designed too.