This may be an odd thing to start with but whats with the story? For starters it uses that weird method of story telling where text boxes are played over gameplay but the two barley interact (IE gameplay never really has an influence on the story nor does any story change up the gameplay). The exception to this is how the setting shifts as the game goes on which is nice, but it's still equivalent to just reading a book separately whilst I play. Then after a while it just stops existing.
Well whatever. The gameplay is what matters most in a game like this and it's good. I was a little confused as to how jumping off of blocks mid air works (still am), I'd assume I'd have to press jump again when a blocks below me yet I spring off anyway and I'm confused as to why, was it because I went in "god mode" holding jump or because I came out holding it? Either way, whilst a little confusing this is a really great mechanic. It feels like it evolves the concept in is done in such a way that doesn't make it a pain to do which is impressive.
My biggest problems lie with the challenge. It feels like easy sailing all the way and then suddenly challenge. The final levels were welcome for their difficulty but a nicer ramp up would be nice as the early game often felt boringly easy. Most stages didn't take too much thought and I still had boxes to spare! When I reached the level that required me to delete the platforms to make the red blocks fall I though "aha, I bet I have to delete them" and figuring this out felt great, finally it was a nice ramp up.
And then,
the game straight up tells me "oh by the way just a reminder of that core mechanic encase you were finally starting to actually solve the puzzles :)" ruining all satisfaction I got from figuring it out. I get this is a slightly new mechanic but it uses established rules so I don't think you have to spell it out to the player, I guess it feels condescending but I was really just pissed that I had the satisfaction of solving the challenge taken away from me.
Going back to the limited boxes thing, as I said earlier most stages, including the last, can be beaten w/o use of all of the boxes. Perhaps this is to accommodate struggling players but the levels already felt fairly easy. If you reward players for using less boxes that might make it feel like I'd actually earned something, else it can feel tedious.
Lastly, a few nitpicks:
-Arts alright, but isn't really nice to look at.
-Being able to jump offscreen and die sucks. Did it accidentally one level and since it hadn't really presented a challenge by that point I was tempted to quit.
-Level 18 was incredibly easy. I didn't have to use any of blocks at the bottom of the level and only had to use one of my two platforms.
-There's little feel or polish. No sound effects, no visual effects like sparkles when I pick up the key or anything like that. Restarting suddenly happens and feels disjointed. No fades in or out. Only polish I really saw was highlighting selected blocks and the door's glowing lock animation. Granted, besides the highlighting selected blocks this isn't the type of game where such polish is vital, hence why its only a nitpick, but I think adding that sort of flair would help the games feel.
Overall, whilst the difficulty is a little wonky, by the end it had introduced an interesting mechanic, built on it and finally challenged me. Technically I didn't notice any issues and as confusing as the block jump is it works well.