i wondered too, for weeks i've been trying to get past the acid pits.

yesterday i got past them, went through the bonus and it just stopped after it totted up the gems and gold i collected.

As I said in the other topic (Montezuma's Revenge) you have to make it through the bonus level without dying.  Die in the first all you like.  To get over the acid pits you have to take a running jump.  Don't stop walking and when you here the edge under your feet hit space (or zero) to jump over while still holding down the left ke.  The second level rocks.

If you feel like a dirty jerk you can rename level02.mzp to level01.mzp in the levels folder but if you can't get past level 1 there's no way you'll get anywhere significant in the second.

Walk to the right and get the potion and the key.  Then do some other stuff and you've completed level 2.  Congratulations.

It's a bonus level.   It comes after level 1 and before level 2.  You die when you touch an enemy or hazard instead of losing health.