In all the talk of graphical downgrades no one seems much preoccupied with 'why?'. Why build something and then proceed to tear it down, piece by piece, in the hope that ever more diminished expectations about the final product won't be severe enough to...
Work out how the gravity affects your jumps in the early stages so you know what to expect later on.
Check the map often in the Adventure mode to see where you've been.
Sometimes it's worth a sacrifice to get to the checkpoint.