Frog Day Afternoon is an interesting small puzzle game created by Chris Clements. The game is available at his personal website, NickelArcade.

The goal here is to move your frog in each level on all white squares, but one time only.

Use the arrow key to move the frog. If you bump into a “?” block, a special reward will appear from the other end. Use the warp zones as teleporters, and get the key to unlock the exit to the next level.

To spice things up, the author added a timer to the game, and your score is decreased by 25 points per second!

Simple and nicely done, Frog Day Afternoon and its 54 levels (at the time of writing) should keep you busy for a while.

Have fun!