The simplicity of this feels pretty inspiring to me, makes me feel like trying to make a game like this myself.
And effectively easy to immediatly understand for anybody right off the bat.
One thing I found to be slightly annoying, is the way the blocks fall down. They snap 1 space down each step, if it's all 1 color in a row, you basically don't see anymotion. And when it's a mix of the 2 colors falling down, it kinda feels like the screen is just bkinking between red and blue, wich gets a little tiring on the eyes.
It might lose a bit of the minimalist style to change that, but I think it would be a little more easy on the eyes to have the blocks fall down in a smooth motion, or at least have like 1 inbetween step, having it more clearly convey the downward motion.