Spider Monkey was just released by Shockwave, along with Tower Up. Some concept art and sketches below.
Above: Original source for spider monkey characters.
Below: Character sketches for modelers.
Above: Photoshop montage combining colored pencil sketches and rough interface.
Below: Refinements based on card specifications applied to levels 1 and 2 of the game.
Below: First pass by modelers with artwork inserted into level 1.
Below: Notes to modelers and animators about position of monkeys and their movement across the top of the game screen such that they don't interfere with game cards or interface.
Below: Examples of level background art.
Below: Final payoff animation. Concept sketch and assets.