This month's "Plug and play" project is a clone of Nintaii, a famous Japanese (I think) logical game that was recreated dozens of times (a clone of it is running on PS3, etc) and will test your intelligence. I only added 5 levels to this project, but since each level uses standard blocks of 64x64x64 quants, you can easily create at least a dozen of levels per hour.
You control the white vertical entity, trying (and hopefully succeeding) to maneuver it towards the goal (the blue pulsing square); use the cursor keys to control the player entity until it lands on top of the goal in a vertical position.
The second level is quite easy; if you get stuck, you can always undo the steps that led you to that position or (if you are lazy) you can press the "Restart" button in the upper left corner of the screen to restart the current level.
The 3rd level (pictured above) introduces bridges and their associated triggers. The player can't reach the destination without filling the gap (activating the bridge) and this can only be done by stepping onto the green trigger tile vertically. Just do that (take a look at the picture below to see what happens when you step onto the trigger tile) and then move towards the blue, pulsing destination tile to finish the 3rd level.
The 4th level is the first one that actually tests your intelligence a bit; it's not a big challenge for a pro, though.
The 5th (and last) level is a bit harder, but I'm sure that you'll be able to finish it.
As soon as you finish this last level you will be greeted by a gorgeously looking (printf-based) "congratulations" message.
The code is very well commented, as always.