Tobias Neukom’s LiquidSketch (Free) for iPad 2 and 3 is a gorgeous water physics puzzler that does things quite a bit differently, to its favor, than Where’s My Water? and Sprinkle. Players intimately interact with the liquid in 90 puzzles based on six different stages and four game-changing mechanics.

While the goal is always to fill one or more boxes with (sometimes specifically colored) liquid, the first set of puzzles uses the gyroscope primarily to splash and mix the water. The next set involves using blocks to build bridges, pathways, and even pressure. The pressure will sometimes help the liquids collide fiercely to reach greater heights or spit out further then if it simply poured out.

Players then experiment with touch-enabled puzzles of pressure, mixture, and flow. Fingers can now flick and funnel liquid with ease through mazes to fill each goal.

The pumps introduced in the fourth set of levels not only thrust water in a certain direction; they also act as mixing agents, agitating two water colors until they blend. The developer finally reintroduces the other mechanics with the last two brain-breaking sets. I admit that I haven’t finished the whole game, but I’m reveling in LiquidSketch‘s mental taxation. The game is engaging enough such that I don’t miss leaderboards or Game Center integration.

To become a little better acquainted with how all the mechanics play together, the game includes a sandbox mode. This mode feels somewhat like a missed opportunity, however. Players cannot create a playable and more importantly shareable puzzle. I suppose that’s the difference between a sandbox mode and a level editor, but this hypothetical editor could really breathe extended life into LiquidSketch.

Without the liquid, I admit the game would also look a little lifeless. The blocks and grid are plain, but I believe that is so they don’t pull focus from the amazing water flowing and mixing simulations. The music, while soft and soothing, also plays second string to the silky smooth water simulations. My analogy: Where’s My Water?‘s Swampy character added the requisite charm and appeal. LiquidSketch’s Swampy, impressively, is the liquid itself.

Along with charming graphics and physics, the game is spellbindingly hard. Solving the puzzles here doesn’t have that “luck" feel other physics-based puzzlers employ: the kind where you watch a solution online, and even when you replicate it, you don’t get the desired result. In LiquidSketch, it’s all about knowing how to exploit the physics.

I experienced only a little bit of trouble placing the blocks on the grid in a few puzzles. I could see where I wanted the piece to go, but sometimes the piece would just go slightly askew. The developer told me that the grid size is a compromise. If he made the squares bigger, the water would look less detailed. I’ll bite, though maybe a zoom feature could rectify that.

In the end, it was mainly my lack of puzzle intellect that frustrated me and not the touch accuracy. Any frustration washes away after seeing the liquid crash and splash; it’s as if I experienced the best part of a beach without getting that annoying sand everywhere. As difficult as LiquidSketch becomes later on, it remains an easy recommendation for puzzle fans.