If there was ever an obscure arcade port Space Dungeon was it. Although Space Dungeon achieved a cult following, it was never a smash hit in the arcades. This makes Space Dungeon an odd choice to port to Atari's flag ship console, but port it they did. As it turns out the 5200 was actually well suited for the odd game, as the non-centering 5200 sticks coupled with the dual joystick holder imitates the arcade control scheme quite well.
The main goal of Space Dungeon is to gather as much treasure as you can and escape the dungeon. Each dungeon floor is a 6x6 maze of rooms filled with treasure ready for the taking. Of course before you can start counting your loot, you're going to have to get past the dungeon guardians first. In addition to treasure, each floor is jam packed with tons of nasty creatures all waiting to get a piece of you.
Thankfully your ship is armed with a 8-way laser that can blast the guardians into the next dimension. Due to Space Dungeons unique two joystick control scheme you can move and fire in separate directions. This comes in handy since you'll be running away from the guardians more often than not, and it's nice to get a few parting shots off before you go. Keep in mind however that in Space Dungeon the monsters aren't content to just chase you out of the room, they want you dead in the worst possible way. Monsters will pursue your ship from room to room, so it's best to take out a few monsters in each room or else you may find yourself with a whole army on your tail.
Although you can collect all the treasures on each floor, it's more likely that you'll only be able to grab a few choice items on your mad dash to the exit. Taking the time to carefully explore each room is a sure fire way to get your butt kicked. By the time you get to the lower levels you'll be lucky to explore more than a handful of rooms. Thankfully the exit is clearly marked on your map at the beginning of each level, so make sure you pay attention to where it is and where you are. Also take note that sometimes when you leave a room it will be temporarily sealed off for a few seconds. Make sure you don't trap yourself in a bad situation with no escape route handy.
There are several different types of monsters that inhabit the dungeon. Some like the Death Square (real original name there guys) are fairly harmless as they don't put up much of a fight, but other enemies such as Guards, Executioner, and Enforcers will pursue your ship mercilessly. There are three special types of enemies to take note of: Pikers, Corner Zappers, and the Thief. Pikers are nasty little creatures that resemble a compass with sharp missiles at each corner. Shooting a Piker will result in a part of it's shield being blown off, but to kill the creature you'll have to shoot it in its center (which is often easier said than done). Use extreme caution when taking on a group of Pikers or you may find yourself in a tight situation.
Corner Zappers are innocent looking orbs that appear in the corners of some rooms. Unfortunately for you, these traps will shoot powerful laser beams between their terminals which can go along the walls and even diagonally across the room! Since they shoot at random times, Corner Zappers can surprise you at bad times (such as when you're on the run from a large group of enemies). Make sure you pay attention to the corners of each room and plan accordingly. The Thief. isn't an enemy as much as he is a pest. Starting on level 2 he'll wander the rooms stealing all the treasure before you can grab it. Shooting the Thief. will result in him dropping all the treasure he's gathered so it can be a big windfall for you if timed right.
While it may not have taken the arcades by storm, Space Dungeon found a home on 5200. The quirky arcade game made a nice addition to the 5200's library and helped bolster its reputation as the "Home Arcade Machine". Although Space Dungeon may have a few problems (occasional slowdown, rooms with no exits, questionable colors), it's a solid game with a good reputation. An Atari 400/800 version was planned but never released in cartridge form (it did however appear as a bootleg on disk). So Space Dungeon remains a 5200 exclusive...