The concept is good, i like it.

The game definitelly needs better, preferably interactive, tutorial. If it wasnt for roast, i would have given up before i figured out on how to play it.

It is weird to see final score be negative. It is logical but strangely not intuitive and personally repelling. Reminds me of game still in development before polishing it out. Maybe limit deduction down to 0 points only?

Dynamic of falling (gravity) could be a bit more attractive.

Also i constantly felt there were too many solutions out there and i couldnt find enough. Meaning, less choices and higher tempo could maybe be more appealing. Making me feel smarter :)

Needs more sounds, especially "success" kind of sound when you add them up correctly.

My suggestion for notifications popup is to pop it up after a few starts. When i start any game for the first time i personally almost never click ok to notifications. Those that ask me after i got to know the game, have a much higher chance of getting me click OK.

Also try to get some designer friend hands on it to polish it up a tad. Luckily for one-man-band programmers minimalistic design is popular these days but it's still quite tricky to get right.

Much of the above is higly subjective personal view of course :) Thoughts to consider.