Thanks for playing. First time anyone has raised the readability thing, and it is a fair point, but I would like to try fixing it without going representational, since the abstract look is most of the point for me.
My guess is the actual problem is that the board does not tell you enough. You cannot see which tiles are about to become dangerous, and a few of the enemy types look too similar to each other. So clearer telegraphing and more distinct shapes are what I want to try first. If that still does not read, then you are probably right and I will have to rethink it.
The puzzle mode idea I like a lot. Handcrafted boards with one correct solution, no randomness, which would suit the game and would also teach people the rules. The endless mode just throws you in and hopes you work it out.