It's well known that ninjas are a stealthy lot, more accustomed to the dark shadows and rooftops than out in broad daylight. It's also well known that ninjas and pirates are bitter, bitter enemies with the reasons for their eternal conflict lost to the sands of time. With N+, we learn that ninjas are also a sucker for a huge cache of gold coins, and will do anything for them, thereby giving us our first concrete reason for the enmity between these groups: theft. The game is both a physics fueled puzzle-platformer and a dramatic telling of the day when ninja first stole from pirate, thereby plunging both of their worlds into madness.

Ok, so I made up the pirate angle, but as for the puzzles, the platforming and the physics they're all in this game—gold too, and occasionally explosive bits, marauding droids and skull crunching falls from great, great heights. Such is the world of the ninja as you direct your character across the 200 single player levels and 150 multiplayer levels. Each level is simple. There's you, the level, a timer, a bunch of gold, a switch, a door and occasionally something that will either blow you up, shoot you or cause other means of bodily harm. The objective is to hit the switch, open the door and get out before the time runs out or before you get killed. Getting gold not only makes you rich, but it also gives you back some time, thereby extending your attempt to get more gold, or get less killed.

It's a simple premise and the visual execution matches the simplicity. Your ninja is fluidly animated, which makes sense as there's not a lot more present in the visuals department. The original was a Flash game, and this upgrade carries the same aesthetic. There's a nice subtle color switching to the background as you play, however this is by no means the game you use to show off the graphical prowess of the PSP.

Not to worry though as the physics in the game more than makes up for any lack of visual flair. Your ninja has an impressive vertical leap, as well as the ability to bounce off of vertical surfaces for higher jumps and the ability to cling to the same surfaces for a slower but safer descent. The game's levels strike a nice balance between levels where the geometry is simple and there are moving disco-ball looking enemies after you, and levels where the geometry is the enemy requiring split second timing lest you miss a ledge and fall to your death. Oh yes, you will fall. Many times. Your ninja may be many things, but bouncy ain't one of them.

The combination of enemies, geography and physics makes for a constant shifting of risk and reward as you start a level. If the geometry is simple it's easy enough to grab the gold and get on out of there. On the more complex levels, what's the priority: the gold or your skin? More money means more time, but it's also riskier. Each episode consists of five levels which must be completed for you to finish the episode, the lack of mid episode saving would have been a nice addition, and the difficulty within the episode varies nicely as well as scales well. This is the type of game where you'll pick it up just to do one episode, but find yourself desperately trying the same level hours later and not knowing where the time went. Getting more gold unlocks items such as more colors for your ninja, more music and more celebratory animations.