I bought this game on sale for very cheap, and while I can't say it's not worth what I paid, because it most certainly is, I just think there was a lot of wasted potential here. The thing is, puzzles in general can be very fun and rewarding, or very frustrating. I think the main thing that makes a puzzle frustrating is when you simply don't have enough information to solve it. Sure, it's a valuable life skill to be able to solve problems even when you don't have all the tools, but those kinds of problems are supposed to give you real life rewards, not present themselves as games and take your money.
My biggest complaint about this game is that it relies heavily on things it never gives you a chance to understand, particularly timing. Many of the puzzles are very simple in a spatial sense, but require timing movements exactly so that you can interweave block paths. However, the game doesn't let you change the speed of the runs, and it's not consistent between different runs. Furthermore, some of the harder puzzles have blocks traveling at different speeds.
As if that wasn't enough, it seems the game doesn't even judge collisions based on a notion of which block occupies which tile, but rather it actually uses hit detection, so blocks entering and leaving a tile at about the same time can still collide by touching corners for a split second. This makes some of the puzzles unnecessarily trial-and-error in nature, with the player just switching blocks around between multiple nearly identical solutions in spatial terms which result in slightly different timing, in the hopes that one of them will eventually produce the correct result. A good puzzle game shouldn't be designed to make you just randomly try things until one works.
Another complain I have is that there's no ability to zoom the camera in or out as far as I can tell. You can rotate the camera, but the level of zoom is consistently too close or far to clearly see all of the map. The game would've also benefitted from a square lense (orthogonal view if I remember correctly from 3D modeling) rather than an eye-type lense, because several of the puzzles have you dropping blocks from one platform down to another below it, and trying to line up the camera from above to see what will happen isn't very effective.
All in all, it's an interesting concept for a game that had potential, but it feels like it was developed to work against you and force you into trial-and-error runs rather than actually thinking about space and time in discrete units with well-defined, known rates of movement. This game could've been more fun in 2D 20 years ago. I found myself using the hints (which make it way too easy) and trial-and-error to solve the harder puzzles, because it didn't even feel like cheating when that's about what I would do without the hints anyway.