I'll get back to the game's length a little later in the review.  This game isn't bad at all, it's just so ridiculously short that it's not worth buying.  But it does have enough redeeming qualities that make it worth renting or playing in the arcade.  Therefore I will concentrate on the better aspects first,

I'm willing to bet that most gamers have never played Ninja Assault before.  Some of you probably didn't even know it existed until this review appeared on our site.  If you've played a light-gun shooter before, then you already know what to expect from Ninja Assault: more of the same.  There is no innovation here, just faster-paced gun-slinging action that'll give your index finger a solid workout.  Enemies consist of evil Ninja-like creatures that will stop at nothing to ensure that you insert your whole wallet into the arcade machine.  Of course, at home you don't have to worry about that sort of thing, but the game is exactly the same.  The difficulty can be altered, making it harder or easier, depending on your preference.

Ninja Assault can be purchased with or without the GunCon 2 (Namco's proprietary light-gun controller).  The difference in price is minimal -- $60 for the game and the gun, $50 for just the game.  Why anyone would want to buy the game separately is beyond me, especially when that's the only way to acquire a GunCon 2.  Even if you already have a GunCon 2 from one of Namco's other PS2 shooters, I'd still recommend that you get another so that you and a friend can enjoy the gun-firing action of Ninja Assault together.  Without two guns, one person must use the standard Dual-Shock 2 controller, while the other gets the fancy light-gun.

Although not as fun to play without the GunCon 2, shooting fans will be pleased to know that Namco has greatly refined the analog control by adding an intuitive lock-on feature that automatically targets the nearest enemy.  It sounds small and insignificant, but the lock-on feature has made Ninja Assault much more enjoyable.  You still have full control over the crosshairs, and can move them around at a nice, speedy pace.  The thing is, Ninja Assault's enemies move much faster than your typical House of the Dead zombie.  Normally, killing every foe would be an excruciatingly difficult task.  With the lock-on feature, all you have to do is move the crosshairs over the nearest enemy and fire away!  The game automatically switches to the next target once the first one is dead.  While battling fast-moving bosses, the lock-on feature makes it easy to shoot those hard-to-reach areas, most of which would have been next to impossible to hit otherwise.

The downside to the lock-on feature is -- yep, you guessed it -- it makes the game easier.  A LOT easier.  Without it, it would have been too hard, and not nearly as fun, but with it, you'll exit the game almost as fast as you came.  Beating it won't take you more than 60 minutes, and that's only if you procrastinate or play through it on a higher difficulty level.  The lower the difficulty level is, and the more continues that you have, the sooner the game will end.  New scenarios will be opened up upon the game's completion, but they're nothing more than rehashed variations of the arcade mode's levels.  There's a level select/time attack mode that can be unlocked, among other mini-games, but none of these add to the game's value.  None of them are spectacular enough to make you stop and think, "Wow, this game is worth $59.99."  For that price, you'd be better off going to the arcade.  There you'd get a bigger screen, a bigger gun and you wouldn't have to worry about what to do with the game when it ends.

Gameplay: 6.7
Ninja Assault's most redeeming quality is also its worst enemy.  The gameplay is good, fast and fun, but it ends almost immediately after it begins.  Truth be told, the so-called "bonuses" are nothing more than a collection of rehashed stages from the arcade mode.  If this game had been longer, it would have been worthy of a much higher score.

Graphics: 4 
PlayStation 2 graphics, these are not.  Ninja Assault was not developed with the PS2 in mind.  I'm not sure what type of hardware was used to power the arcade version, but the washed-out backgrounds, weak-looking characters and blocky environments make Ninja Assault one of the least visually impressive games of the year.

Sound: 5
Ninja Assault's sound is a usual mix of gunshots, monster-like noises and average music.

Difficulty: Medium
By most accounts, Ninja Assault is easy, but if you tried to beat the game on its hardest difficulty level, you most certainly wouldn't succeed.  It'd take a lot of practice to master that one.

Concept: 5 
You know how some people seem like they're not all there?  You talk to them, and the things they say don't make much sense; their sentences aren't complete and they don't always sound very logical.  That's kind of what it feels like to play Ninja Assault.  In many ways it's this great person--er, game, but there is so much missing from it that it makes you wonder if the game was dropped on its head a lot as a child.

Multiplayer: 6.7
Two people can blast their way through the game simultaneously, making this a fun way to kill an hour or two on a boring weekend.

Overall: 6.5
No one should be expected to buy a game that takes an hour to beat.  I understand that the developers wanted to bring Ninja Assault home to PS2, making it available to a much wider audience.  And I'm sure that there are some diehard light-gun fans who will be thrilled to own the game, even if they don't play it very much.  But there's a certain level of gameplay standards that have to be met before a game is truly worth purchasing.  Not much can be expected from arcade shooters, all of which are intended to be short games.  At $1.00 a game, that's acceptable.  At $60 for the whole enchilada, it's hardly worth adding to your Christmas wish list.