
If one dies while on the bike, but not having activated the checkpoint, $B7-$B8 gets written with 0! Which means objects are loaded right from the start of RAM. When it has, config pointer (loading level objects from the ROM) gets written to $E5-$E6, and it's copied to $B7-$B8 when the toad dies. The intended logic is to restart level 3 only if the race track checkpoint has been activated.

You must go over there quickly because the warp will disappear before the snake gets there.

In Level 6 (Karnaths Lair) in the 2nd Snake pit, climb on the first snake and run to the right all the way down when the snake reaches the highest point of it's path (don't hit the spikes) there should be a warp on the other side.
