My first custom block. Stick it under your normal lava surface. The player will take damage and bounce high into the air. If already small, he'll die. Kills sprites on contact too.
Rejecting this because the SA-1 conversion you made is incomplete: the sprite addresses haven't been remapped, so the block doesn't do anything with sprites on SA-1. This has already happened a handful of times with updates you submitted: please test your resources thoroughly before submitting them (and if your update is supposed to be SA-1 compatible, test it on a SA-1 rom as well).