During the mid-game puzzle with the waterfall, when i attempt to descend to get to the third cave the game closes completely, i've tried several times but nothing changes, is anyone else having this issue?
I haven't experienced the issue myself, but the ScummVM enginge is known to crash if some script errors occur. This can happen in some games, if you reach a game state, that shouldn't exist (at that point), e.g. by doing in-game something to often, to early or in the "wrong" order as expected by the game. The crash is repeatable, because the wrong state is manifest in your savegame. Hence, you can try to use an older one, that isn't faulty or even start the game over (now that you know the puzzles). If you want to be sure, what to do in the right order to reach the point you are now, you could consult a walkthrough.