Continuing where Gunbrick left off, Nitrome created another tiny sized game that you can either play in a small window or zoom and face the blockiness of the graphics!
J-J-Jump is a platform game where you have a limited number of jumps (up to 5). After that you have to reacharge by picking up any glowy bit on screen, which grants you back an extra jump. You also can chain jumps so you can get to higher platforms. Of course you mustn't get carried away and jump uncontrollably; you have to learn to count your jumps and leave a few spare because you don't know what lies up ahead. Finally, to give the player some pressure, the water level keeps rising so you have to be quick about what you do or you're going to get your feet wet :).
The game plays really well and despite having some tricky jumps it never gets impossible (well, except for the last level, but still it's doable). Each level is filled with checkpoints and you have no lives counter so even though you have the pressure of rising water level it doesn't feel like a big bother.
In any case, 15-20 mins of platform fun await you if you play this game!