quite nice! I made it all the way to level 9, which is stumping me rn. I liked the intuitive succinctness of the mechanics. There were no weird edge cases as far as I could tell.
rot13: V guvax V purrfrq yriry rvtug. V qvqa'g hfr gur hzoeryyn ng nyy. Vafgrnq, V chfurq gur pengr hc juvyr vg jnf gur jnyy, gur png zbirq, fhccbegvat gur pengr, naq V chfurq gur pengr nybat jvgu gur png gb gur tbny. Vg jnf fgvyy n sha fbyhgvba, ohg V qba'g guvax gung jnf vagraqrq yby