Fun
I like the simplistic graphics and the music is nice, if repetitive. Plus the physics are pretty good... Except for the fact that the blocks appear to be made entirely out of rubber.
However, I didn't like the fact that you had to wait for the timer to finish checking if you knew you were going to lose. The refresh button doesn't work while the timer goes down! Not only that, but you put the timer in some categories that didn't even need it! The long ass waits made me want to give this a 6, but I realize this is a small game element. Besides, there should be a way to speed up the motion of the objects so that you see what should have happened in, say, 60 seconds, in three seconds. While statements come to mind, but I know that if you had a flawless setup you'd end up with a broken computer. Still, I'm POSITIVE there's a workaround that you didn't think of.
I also didn't like that the menu didn't show if a level was beaten or not. A check mark over or glow effect would have been a nice indicator.
As per individual modes... Collapsing made me frustrated because the blocks had way too much friction, and I lost in ways that would be impossible in real life. Building was easily exploitable by stacking things against the walls. Stacking got way too hard way too fast, and the way that balls rolled on their own was a small thing at first but became impossible to work with eventually. Moving seemed to require a good deal of bullshitting and cheap Jimmy-rigging. I didn't get to see too much of Exploding because I couldn't figure out how to beat 4, but I did manage to play at lest 6/7 of the levels in all the other categories.
This game DOES NOT present itself as fun. It presents itself as ANNOYING AND FRUSTRATING. It is possible to make puzzle games that do not fit into this category, but this attempt failed hard. I'll still give you a 7 for the presentation and the physics, which were nice, though the level design was not.