Thanks for the comment! yea in hintsight i really should have made things more clear to the user. Excuse my bad habit as im a Backend-developer and as this is my first Jam i missed out on having it playtested by someone who wasn't on my team... Next time!
Tips for you:
Only one stone needs to touch altar but it needs to have the right weight.
weight (yours and stones) is changed by having them be in a red(heavier) yellow(normal) green(lighter) circle
in the second level you need to throw the stone over the red zone!