oh wow what a clever little tetris like experience ...
not gonna lie, I did not read the description and went directly to the game ... felt confused for 5mins, when I figured it out I genuinely felt I had solved a puzzle (seeing a screen full of numbers does feel like a puzzle already) and was hooked then .... I do not know if you implemented an idea that already exists but it was new and clever for me very much so ....
so regarding the question about making it more understandable .... if you make the first few blocks fall as if it was a cutscene, then match the numbers in the floor, I am sure 95% of players will already understand there is something to do with colors, and some math happening with the numbers, the ones that would like this type of game will already feel hooked for sure.