The game does have some flaws that could have been easily spotted with some testing. Don't get me wrong, the soundtrack is very fine, and the graphics are okay despite being essential.
I gave up at the second ice cube stage after the red messages. That's where the difficulty spiked beyond reasonable enough to have fun.
The main issue here is that the obstacle hitboxes, and I say box, are huge squares that you unavoidably hit most of the times when there's a narrow jump to make. Any diagonal jump gets you killed by either the spike you're trying to jump over, or the spike above. You have to time your spacebar and arrow key in such a precise way, it stops being fun and starts being aggravating. This displays especially in the purple and small box levels.
Worst of all was the first ice level after the stop messages. I think I took about 200~ tries, which made me give up at the following ice level. You have to pull 8 precise jumps in a row. Overshoot, undershoot, or mess up your arrow key tapping, you go back to square 1. The worst part was dying to a cheap ceiling spike after 7 precise jumps, which I probably 'hit' with a corner of the box. I decided not to go through the second 'hard' ice stage just because of how many narrow jumps I saw in it.
Giving the player a time limit was not needed at all, the difficulty lies in the narrow timings and jumps already. And for a game this hard, not having a level select / save feature makes it much less enjoyable, since you can't complete it another time.
For a first game, it's a great result.