thank god for easy mode. starting from the first jump after the second cutscene it's basically mandatory. came back trying to get the last secret medals but after two identical playthroughs i have absolutely no clue, so i guess it's gonna stay a secret
edit: i'm gaming; can confirm the "true love" medal is obtained from clearing the game on normal difficulty.
turns out there's a difficulty spike right at the beginning of the game (after the cutscene with the spaceship) where all the jumps are considerably harder to land then the rest of the game, which is what put me off from attempting it, thinking it would only get harder (which was not the case).
even then, the checkpoints are plentiful and you get infinite tries at every jump, so it's really not as frustrating as i recalled it.
for anyone struggling at the jumps on the slopes:
simply walking down on a downward slope won't let you jump far enough, and sometimes will just eat your jump input.
to cross wide gaps, you have to directly land (from mid-air) on the middle or lower part of the downward slope and jump as soon as possible, as you will slide and jump farther than normal.
keep in mind that walking to the middle of the slope will just make you slide off, and most of the time you'll just fall to your death anyway because the controls are finnicky like that; wouldn't be surprised if i managed to perform this correctly once every 20 deaths.
if you want to stand on a slope without sliding off (for example, jumping toward an upward slope), landing on the top corner of the slope is the same as walking on flat ground; just be wary of your character momentum as it tends to walk off anyway, and the foodhold is overall small.