Arbora

Arbora is a tile-laying game with a (very thin) environmental theme. The 36 tiles depict silhouettes of different kinds of leaves or branches, four on each one (one per side). These are placed on a 6x6 grid in an effort to complete 2x2 squares and rows of 6 (both of which get you points).

Since each picture has only one match, so once one tile is placed on the board (which is randomly done to start the game), the entire layout is determined, and players simply can choose (so far as their draws let them) when to play which tile(s).