Using small cut-scenes for storytelling, trying to give sense to the action happening in the game, Puddle follows the journey of a small puddle of fluid changing in nature (or several puddles of different stuff? It's never really clear) that the player needs to direct through several types of environment divided into 2D side-scrolling stages, from a start point to a finish in each. This is harder than it sounds because of the dangers awaiting in each zone and the fact that some fluids aren't as sticky as others, meaning they won't remain in one tight pack from start to finish but rather break into tinier drops. As much liquid as possible must be brought to the exit, as quickly as possible. Failing to keep enough fluid means failing in the stage. Fortunately, for the harder stages, there is the chance to skip it. However, this can only be done four times, so going back to clear it on will be necessary to get that "Joker" back for skipping other stages.
This is done by tilting the Wii U Gamepad left or right, which in turn tilts the in-game world. This forces the fluid down the slopes the player then makes. Using the momentum built up while going downhill will in turn help the little puddle go up hills as well.
The TV screen and GamePad show the exact same thing, albeit in different resolutions. It is probably better to play using just the GamePad since it makes the most sense, given how the game world is right there in your hands, tilted as the GamePad is moved. If not, the eyes tend to be drawn to the little screen anyway. The big screen, meanwhile, is ideal to show off the game to friends or family. Unfortunately, a subtle delay happens before the GamePad is titled and this is reflected on the screen, which at first will seem a bit unresponsive. Why that happens is incomprehensible given how gyroscope works superbly and responds instantaneously in games like ZombiU when scanning around with the controller. Clearly the fault here doesn't lie within the hardware, but rather the programming.
That being said, it's still playable enough but will require some anticipation on the player's part. It should also be noted that, unlike Hydroventure, the game world can't be turned upside down, but only tilted left or right up to a certain angle, which feels a bit limiting when one has already tried Hydroventure before, but makes sense nonetheless given the somewhat more realistic / less fantasy setting of the game.
Not only is there direct control of the fluid, but also various containers that require cautious handling to avoid breaking or overturning them, spilling their contents since those will protect the fluid from environmental hazards.
Each type of fluid has its own properties, and they come in a wide range. Starting off easy enough with coffee and water, which don't really have any particular properties put to use at the start, it quickly shifts to more complicated affairs, such as fertiliser that must be used to make plants grow, leading the fluid to higher places, or even weed killer to destroy plants blocking its path but that in turn gets destroyed by certain types of plants. It seems to get more and more interesting as the game goes on, going from what initially seems rather uninspired to borderline genius later on.
The fluid changes in nature with the environments, with the aforementioned fertiliser and the like found in the forest while later on there is oil and nitro-glycerine found in a lab. Graphics seem to be made from a mixture of realistic looking computer generated stills of natural objects, digitised pictures of real life objects, and plain black shadowy elements.
Puddle is a resolutely 2D game using HD assets that makes for a quite enjoyable art style, completely making sense with the type of game and its mechanics. It gives a sense of "chemistry lab experience" in a sense, from the characteristics of each fluid being explained as new ones are encountered, down to the rank given to the player using the atomic symbol of the element used, gold being "Au", silver being "Ag" and copper being "Cu". It's a little touch that may seem totally unimportant, but which, along with the rest of the game, shows a careful approach to making a consistent experience.
Beyond the main goal of reaching the exit of every level, there's the challenge of getting the aforementioned gold rank in each stage, which is done by clearing them either really fast or keeping as much fluid as possible until the end, or a careful combination of both. A few additional challenges, presented like an achievement system, can also be attempted, also adding to the length of the game. Finally, online leader-boards are there as well and serve as an invitation to improve on personal scores, showing the world how skilled you are!