A great little "time waster" to keep your brain sharp. My kids love it too.

This game has an inverted difficulty curve, and an inverted fun curve as well.

The first levels, the 'Easy' chapter of the campaign, had me grunting WTFs at 50 rpm. mostly due to the (ugly) clutter and the UI's inability to smoothly place certain pieces.
The clutter makes a lot of positioning feel like pixel perfect.
So do the background/foreground interferences, which are never clarified (my pick for the game's main flaw.)
The problematic pieces are notably the cogs, which hardly align, and the cables (and electrical appliances,) which hardly attach and are blocked by most things (including the appliance they belong to.)
Rather frustrating.

Nonetheless, the following chapters showcase a large array of much better designed puzzles, with more flexibility, clever solutions, and amusing effects.
The majority of the game is really fun to play.
(As long as you remember to zoom in to place the occasional cog or cable.)

The impressively large quantity of pieces brings novelty to pretty much every puzzle.
Themed bonus chapters, all but 1 also excellent (the roller-coaster one has the worst piece placement, in 3D, and buggy physics that kick the ball out of the track for no reason.)
Bonus mini-games, which I personally don't care for (no hard feelings.)
Plus an editor for your own creations to share, always a positive in my book.

Meh.