I really like this. I'm revisiting math after a couple of decades off, and my son is getting into pre-calculus-ish topics in school, and I'm going to share it with him.

It definitely has a few rough edges, though. The equation in the first screen has the right behavior but is complex enough to probably be concerning for the target audience, and I'm not sure it clearly spells out what the player is going to be doing in the greater game. `y = x` is a great actual starting point and it clicked for me then. I'm not sure how to thread that first-level needle from a design perspective, to be honest.

Again, though, I do really like it. There's some trial-and-error on each level (at least for me) but I think that's part of what could make it an effective learning tool.