I was thinking at first it was pretty self-explanatory, but I didn't realize until well into 1000 points when I was completely stuck that unlike most other match-3 games, you could swap even without a match. And I never did figure out why some words just sat there and blinked red on every move instead of clearing out the letters. So, actually not that self-explanatory after all.
Hi, thanks for trying it out! I just uploaded a new version with an introductory tutorial that hopefully explains all that better. (Tapping the bottom of the title screen five times resets the save data so the new tutorial would show for a returning player.)
I started this just as a little exercise but think I want to build it out more with powerups like match-3 games have and improve the gameplay and balance, so if you try it again, I'd love to hear any more reaction you have.