In level 2, one of the diamonds (the last one at the right side of the map) can't be grabbed since the highest jump of the player will never be high enough to do so.
Fixed using POKE 39293,14: POKE 39541,14
Near the end of level 4, the game starts showing some graphic corruption if the game is played without sound: "In simplest terms, for some reason the game uses paging as if it were a 128k game?!? It then writes a couple of values into the are a that it has just paged (which hasn?t paged obviously) and this area is the screen update section. From this point the bug quickly manifests itself as this code is copied multiple times to various parts of memory.
This bug only occurs with the sound OFF. If you turn the sound ON, it won't happen."