Ok, someone spoil me. How do you access these three areas so far that seem to require a higher jump?
Cheat engine, they are unfinished :) there is no leggit way to access them.
In the boat:
it's the same for most doors you cannot open, they lead to unfinished rooms with no enemies or the dreaded teleport room (the green ones on the map, which put the game on infinite loop if you activate the stainglass)
Anyway, this demo is at last a proper engine, and navigating the map will properly move you. the older demo created limited sections of rooms in 3D and if you tried to move yourself in a virtual map the engine would make you fall in the void.
There is much much much progress, and that's good for modding/cheating