Why did the chicken push the boulder? Because it was in this Sokoban variant, of course.
Have you played Sokoban before? Really? If you haven't, download this and realise that you just didn't know what Sokoban was called before. Its that game where you push blocks around, but can only push one at a time and in one direction. It's a puzzle game and in this particular version, you get to play as a chicken.
While the game goes nowhere new - where could you go, really? It does fare well with the puzzle elements it has. There is a counter for how many moves you've made, scores and - impressively - an 'undo' button for that time when you accidentally push one block too far. Don't you hate when that happens?
Apart from that, though, its a standard game with standard graphics. It offers the same amount of puzzle as the variants before it.