Sometimes it's hard to see the wood for the trees — but in the case of this optical illusion, it's a single leaf that's proving elusive.

Released to mark Earth Day this weekend, the puzzle challenges eagle-eyed players to spot the oddly shaped leaf in the tree's bright green foliage.

Its creators at say they included one leaf shaped like a "foot" in the "ocean" of leaves on its branches, to highlight how important it is to be aware of the footprint we leave on planet Earth.

So can you spot it?


Were you able to spot the single rogue shape among the identical leaves?

It has been circled in white below if you're still struggling.