I'm sorry but I thought this puzzle game had no content.
I mean sure the system of equations were challenging, and I liked that you made them so the answer didn't need to be solved on paper but you can use mental math and "math-tricks"...but there were only like 4-5 questions. There weren't any different types of questions, and it seemed very unprofessional (layout and whatnot) and unaesthetic.
If you want to really make such a game, consider a bit better graphics (just a bit), more math puzzles, different types of puzzles, etc. And then it also becomes an educational tool as well!