Grow is a long-running game series, with the original game launched in 2002, if I understand correctly, and comprising at least six different games (Grow v.1, v.2, and v.3, Grow Cube, Grow RPG, and Grow Tower) united by a single gameplay mechanic. One might even say that all six are reskinned versions of the same game. Gameplay-wise, things couldn't be simpler: you are given a central play area (typically a planet) and set of up to 12 buttons (the exact number depends on the game), and your task is to press them (or rather drag them onto the gameplay area) in the correct order.
Each button represents an object (plant, building, character) that needs to be added to the world. Moreover, each of these objects has multiple levels of development, growing in reaction to new features placed on the game world. Your aim is to develop all objects to their maximum level. You start out by pressing buttons randomly, but through observation of the interaction between different objects you can start to divine the proper placing order. This is a surprisingly complex task, given the apparent simplicity of your possible actions.
And this is the most interesting design decision of Grow: Where many games appear to disguise the paucity of player choices by complex graphical or descriptive effects, Grow's single-minded focus is on showing the large number of permutations arising from ordering just a handful of actions. The game appears excessively simple, until you realize that it's actually quite hard (or at least time-consuming) to solve.
The emergent complexity is underscored by the relative opacity of the interactions shown (an object growing from one level to another can trigger the same effects as when it's being newly placed onto the game world) which, in the end, probably means that trial-and-error will feature strongly in all attempts at finding the solution (it sure did in mine). This makes Grow more frustrating as a game, but also more effective in showcasing its complexity.
Additionally, slick and cartoony animations serve to even better disguise the game as a nice casual distraction, particularly if one does not pause to calculate that the possible number of moves is (number of buttons) factorial, i.e. n!. In case of Grow ver. 3 (and its remake), this is 479,001,600 meaning that contrary to my earlier statement, a trial-and-error approach is completely futile.
The link leads directly to a page featuring Grow ver. 3 remake (i.e. the version of Grow 3 updated for the latest flash player), but all the other Grow games are accessible from a side panel on that page. As noted, they are identical gameplay-wise, but later games (particularly Grow RPG) add an extended cutscene at the end showing the amount of success you have achieved.
N.B.: For the impatient, there's a walkthrough at Jay is Games.