First of all, thanks for playing and leaving your opinion!
Yeah, more visual effects like some jump or dash effects, some particles as well and better sound effects would have been nice, but I spent almost all the time with the movement, the level design and the basic sprites, so I couldn't afford to do more juicy things, but yeah, that would definitely make the game better.
And I agree that it's unforgiving, but I made it on purpose, I think that's the fun of the game, having to play almost perfect and trying not to make any mistake, like if you were a speedrunner; that's why I implemented the time cheat as you said, knowing that the game is pretty hard and to give the chance for "non-tryhard" players to complete the game without having to hone their skills.
About the manual reset, as I said, you can't afford to make almost any mistake, so if you know you won't reach your objective you can use it to avoid wasting time, I think having to wait until the automatic reset knowing that you have nothing to do is annoying and frustrating. For me, admitting my defeat just encourages me more and makes me want to get better and do it better the next time, concentrate more (I'm not saying that you're wrong and I'm right, just giving my vision).
Anyway, even if we don't completely agree on our visions thank you so much for the feedback and for giving your opinion and vision, is always nice to know someone else's opinion that doesn't think as you.