It is a very fun game, I could see it being used to learn kids math. But the difficulty is maybe a little hard in the beginning. Got myself stuck a lot of times at 29 math problems right. But that could be just me.

The graphics and sound effects are really good, they give it a fun feeling.

What I really dislike is that there is an ad while playing the game that obstructs the '0' button for a bit. I didn't click it by accident, but I could imagine that it could happen and that it would be frustrating when you're on a streak.

The idea is fun. Really feels like an old school rogue like.

I would rethink the combat of the game. Because as it is now, combat is just not a valid option to complete the level. I first tried fight the three skeletons, but they cornered me, so I had to fight them all and because my attack damage is so low, I could only defeat one before dying myself. Then I restarted and tried to run up and past the skeletons, but that didn't work either because they would just block the way and I had to fight them and die again. So I would try to pay some more detail to level design to give more options to the player. Maybe let the skeletons only come to you when your within a certain radius of them and let there be more paths to the end because the only way I found to finish the level was by directly running right and up to the exit without trying to defeat any of the skeletons.

The slow passe of the game adds to the suspense, but it wouldn't hurt if the enemies took their turn a little faster.

I really like the pixel art graphics and animations.

EDIT: I managed to defeat all skeletons by singling them out and then attacking them. But when I then got to the exit, the game wouldn't end the level and I got stuck.