From the publisher:
Cactus (based on the game TRIBE, designed by Naotaka Shimamoto and published by itten), is a dexterity friction balance game that has players competing for flowers in the desert by stacking strange colored shapes onto cactus! Cactus shares around half of the overlapping pieces with tribe, with the major changes being a re-theme to the desert (my home territory!). The piece sizes have been reduced by around 50%, there’s a new color scheme, and a lot of fun new shapes! The rules included are also slightly simpler than the original, and both versions can be played.