I'm sure most people have played this game by now, and the videos already posted in the other guides are fantastic, but I just wanted to upload some higher-def screenshots of each puzzle. I figure it makes it a little easier than watching/pausing, especially if you're trying to do the achievement for beating it in 25 minutes.
Act 1 has two puzzles.
2A - Lighting Failure also has two.
2B - Hostage Situation is only one.
3A - Direct Route has two puzzles, it also introduces the Y button to remove pieces, and the little blocks that explode after a laser touches them for a while.
3B - Across the Rim, only one puzzle. (3B/C/D and 4 all only have one each)
3C - Spacewalk, only one puzzle.
3D - Interior Route, only has one puzzle too.
Act 4, only one puzzle, and the final one.
Like I said, the videos and other solutions are already great, but I just wanted to add in some clearer images.