When you play a game such as Ambrosia's SketchFighter for Mac OS X, the word "novelty" springs to mind.

As the name implies, SketchFighter looks as if it was sketched directly onto graph paper, albeit better drawn than my doodles. This means most of the game is played out in black and white.

Color is used sparingly, alternately to attract attention (flashing red boxes warn you when a boss is ahead) or to show you objectives (you'll need to find the right colored gun to break through corresponding colored barriers.) The lack of color and offbeat graphics give the game a clean, minimalist design that works well.

A look at the program's full name, SketchFighter 4000 Alpha, shows you that Ambrosia is clearly trying to replicate the semi-ridiculous arcade games of the '80s. In keeping, the game play harkens back to simple joystick games such as Galaga or any 2D fly-and-shooter.

Using the arrow keys to control your ship (along with the spacebar to fire), the game is simple to pick up and nice for laptop gaming. Basic play consists of flying around the level and shooting the enemies you run into.

Slightly more advanced objectives have you tracking down various lasers and guns to proceed to new levels (i.e., you'll need a green gun to open green barricades, a red gun to open red barricades). At the end of each level is a boss, defeating the boss will unlock new weapons and gear, and also allow you to continue onward.

While the game doesn't offer much depth, its simplicity and ease-of-play makes it quite addictive. There's not much of a learning curve involved, but some of the boss battles can be fairly tricky and strategically placed save-points mean you'll probably end up repeating a few sequences over.

The fairly catchy game play, retro-inspired design and pen-and-paper graphics don't make SketchFighter a great arcade game, however. No, the multiplayer mode makes it great.

You can play in either co-op or versus mode over the Internet or on the same computer. What makes SketchFighter's multiplayer unique is that both player's ships are tethered together, turning versus battles into a strange, and very entertaining, tug-of-war situation.

Overall, SketchFighter 4000 Alpha should satisfy both casual players who want a game they can enjoy in small 30-minute bursts without too much challenge, and also more experienced gamers wanting a slightly quirky game inspired by old arcades.

SketchFighter is not rated by ESRB, but contains mild violence. It is available for Mac OS X as a download from the Ambrosia Software website. It retails for $19.00.