I've played the whole game, and I thought it was a good game. It's good enough that I thought it deserves a full-fledged review. Also, a review would give you the most feedback. But before starting with the review, I'll clarify the system of rating I'll be using.
(5/10): very average.
(6/10): fine.
(7/10): good.
(8/10): very good OR solid
(9/10): great.
(10/10); masterpiece.
Gameplay and level design (8/10):
The gameplay to me is the most important part of a game, and it's solid here in my opinion. The game is separated into chapters, where each chapter introduces a new phenomenon of the "Pillar" (the names in "" might not be very accurate), and each phenomenon plays out as a mechanic on which the 'levels' of the whole chapter are structured. The plentiful checkpoints and the simplistic level design make for a fun loop of experimenting by dying again and again. I also like how physics and momentum play a big role in the game, making experimentation even more awesome. The level design might be simplistic at first, but it becomes more complex as the game progresses. The flow of the game was generally very smooth so no tutorial was needed at all.
However, I felt that some mechanics felt not very fair nor all that skill-based, as they depended more on luck and blind timing. These include the "exploding seed that sends you further", and the "beating heart". The mechanics I liked include the rest, with my favorites being the "disappearing platforms", the "bubbles containing crystal shards", and the "laser beam crystal". There are also the "timed bombs" that despite being timed, they felt fair and more predictable in behavior, which allowed me to form techniques to overcome them.
The physics is overall perfect, but I have two complaints. One is that the jump height cannot be controlled much and is always very high (you could transform into a ball to reach a low height, but this is still not controllable). Two is that the deceleration is not fast enough to allow for the very precise platforming required by the game in some instances... it's not as bad as the original Crash Bandicoot, but still not great.
The checkpoints didn't work all the time, especially when going back and forth between different sections of the level (which is required a lot). It was annoying but didn't kill the pace of the game. There is also missed potential... you never tried mixing different mechanics together, which would have allowed for endless possibilities.
Overall, the gameplay was solid enough to guarantee an 8/10, but the problems here and there held it back from greatness.
Graphics and animations (5/10):
The graphics of the background and the terrain were generally fine, and the character models were good and beautifully animated. The backgrounds are static and the terrain is empty. This would be a 6/10, but there's one big problem that made it 5/10... and that's the fact that some backgrounds and terrains obstructed my gameplay. For example, the "wind turbines" were hard to make out against the bright background. Another example is that at some point, climbable terrain and spikes were hard to differentiate.
Story and world building (6/10):
The story is simple and likable, but is not expanded upon in many areas... e.g. useless characters, I won't be going deep on why the story is not very strong as a standalone, but I'll be mentioning some of the big problems. Dialogue is inconsistent, and has many grammatical and spelling errors, and many things go unexplained (without being mysterious). There is some needles swearing that was not there at the start of the game. Most importantly is that the story talks about stakes and dangers... in a game where you experiment and die in order to learn. This makes the story feel detached from the game. Despite all that, I still liked the general theme of the story, and as I said a few lines ago... it's likable. So it's fine I guess.
Music (7/10):
Not much to say here; the music is nice and simple, and blends well with the overall atmosphere and story beats. Nothing spectacular though. Overall good.
Overall enjoyment (7/10):
The game is short with little to no replay value, but it was enjoyable enough. I never ran into any game-breaking glitches, and despite some aspects of the game not mixing well with the gameplay, the flow of the game never really stopped, and that's a good thing.
Overall Game Rating: 7/10
Just keep in mind that this is my first time writing a full-fledged review ever. Hope my feedback was useful!