So even though they aren't perfect, does the backflip or triple jump prevent the game from being enjoyable?
Sometimes. The backflip issues brought down everything else. The reason I didn't want to backtrack in the turquoise area? The long backflip-requiring sections, particularly through areas with shooting enemies. It's something that, if I wasn't testing the game for you, may have just caused me to stop playing and go on to something less frustrating.
I'll try and make backflip less necessary like the dive, which sort of became a replacement for a sprint (which I like).
Almost impossible? The timing is already pretty generous. If it was any more generous you'd be doing triple jumps on accident too (Working on making backflips non-accidental, but the happy-medium is super tough to get). Hold-to-jump could fix the problem, but I don't really like that in games. Jumps feel less intentional.
I normally find the triple-jump really easy to pull off, except sometimes near ledges where the last jump doesn't always fire for some reason. I mean, I don't even jump at all when that happens and I end up just falling into spikes or something even though I smashed my jump key audibly while my character was on the ground. That only happened in one spot, though (turquoise area).
The only thing that really gets in the way of the triple jump for me most of the time is...can you guess? The backflip. I'm tempted to suggest that a backflip should count as a first and second jump because it throws off the timing so much, but that would probably break too many things.
Hold-to-jump sounds terrible to me, for the reason you mentioned.
Maybe that's because you/I are/am pressing the button before the character hits the ground. I mean, visually he hits, but for the physics system it doesnt. I always add a 50-100ms of input ghost for this, so when the character hits the ground, the input still counts.
I might just have to stop changing the triple jump and backflip for the most part. I think I'm at the point where any changes I make to fix a problem will only create another.
I sometimes have this feeling too. Well its always your choice.
The triple jump window is checked with the collision system, which is checked before jumping, so you can jump at the exact moment you hit the ground and have it still count. I think your problem comes from confusion with the solid black outline objects have.
There may also be very rare instances where the triple jump wouldn't go off for whatever reason but your issue sounds pretty consistent, so it wouldn't be that. With the exception of these rare occasions that I could never pinpoint, the backflip and triple jump not working is because of "player error." I put that in parenthesis because it's usually due to level design that doesn't synergize well with the mechanic (which I'm fixing). It's like the issue platformers with double jump face where a player might run off a ledge and jump but "not have a double jump" because they lost it when they ran off the edge. It's tough to fix without adding crazy exploits or making it too easy to do on accident.
So along with the other stuff I need to add I'm just going to change the level design itself, not the physics/activation/whatever code. The next update will probably just be the finished game.