Stacking is a fun, short game by Double Fine (they also made Psychonauts). In Stacking, everyone is a matryoshka doll - you know, the russian dolls, that can be stacked one inside the other. You are the smallest doll of all, tasked with finding your family, who was abducted by an evil baron who enslaved them, and use your ability of stacking inside of bigger dolls, to control them.
Each doll has a unique power, which is used to solve puzzles. This powers can be anything - one doll can do a punch, one can shake hands, one can shovel coal, or maybe you have a child doll, which can just blow bubbles. Many are just there for fun, but the puzzles all have multiple solutions, and with different dolls, you can solve them in different ways. The puzzles are a bit point'n'click adventure game-y, but with multiple solutions, it's not to hard to find one. Also, there are three hints for one solution, with the last one spelling out what you have to do. I only needed that ones, and that was just because I misunderstood the power of a doll.
It is pretty short, with only four levels (I beat the main game in 3.7 hours), but there is a second adventure, that I haven't played yet. Also, the game encourages you to find all solutions to a puzzle (the puzzle becomes unsolved again, which doesn't hurt your progression, that still stays). Also, most levels have an extra challenge, also with multiple solutions, which I didn't try (I just wanted to beat it, before going for extra stuff). There are also other small things you can do. And just trying out different dolls, and what they can do, is fun in and of itself. To give you an idea of how much side-stuff there is, I only got 50 %, at the moment, the rest is finding unique dolls (many exist multiple times inside a level, but some are one-of-a-kind) and finding unique solutions.
Also, it looks great. The FMVs are made in a silent movie style, where the text isn't spoken, but shown on an extra screen. They look great, and the whole game is just fun to look at. It shouldn't be expensive (I guess 9.99), and I'm sure I got it during a sale for 3 bucks, or so. I recommend it, it was nice and fun.