The object of Bosconian is to score as many points as possible by destroying enemy bases and ships. The player controls a small fighter ship that can move in eight directions and can fire both forward and backward. Each level consists of a number of green space stations that must all be destroyed to advance to the next level (a semi-transparent mini-map helps identify their location). Each station consists of six cannons arranged in a hexagon, surrounding a central core. The player must either destroy all six cannons or shoot the core to destroy a station, and in later levels the core is capable of defending itself.
Additionally, the player must avoid or destroy asteroids, mines, and a variety of enemy missiles and ships that attempt to collide with the player's ship. Enemies occasionally launch formation attacks — destroying the leader causes all remaining enemies to disperse, but destroying all enemies in a formation scores extra bonus points. A spy ship (worth a random bonus value) also appears occasionally, which must be destroyed or the enemies will go berserk.
Throughout the game, a digitized voice alerts the player to various events:
- "Blast off!" (level start)
- "Alert! Alert!" (enemies attacking)
- "Battle stations" (enemy formation approaching)
- "Spy ship sighted" (spy ship appears)
- "Condition red!" (enemy attacks become more aggressive; occurs when the player takes too long to complete a level)
Like many games made during the Golden Age of Arcade Games, the game has no definite end, continuing until the player has lost all of his/her lives.
Similar to Galaga, Bosconian "rolls over" from Level 255 to Level 0, causing the game to behave abnormally during this level. If the player can successfully complete Level 0, the game continues to Level 1 as though the player had started a new game. Also, after the first ten levels, some of the previous levels will repeat in placement of the space stations (the only differences are the direction of the opening in the stations, the number of asteroids astray in the levels, and an increase in the number of enemy ships needed to be fought off).
It was ported to several computer systems, including the Sharp X68000, MSX, Commodore 64 and the Sinclair ZX Spectrum, and later appeared in several of Namco's Namco Museum compilations for PlayStation and other consoles. The game has also been seen in Jakks Pacific's TV game controllers. A home computer sequel, Bosconian '87, was released in 1987 for the Amstrad CPC, Commodore 64, and ZX Spectrum. An arcade sequel of sorts called Blast Off was released in 1989 only in Japan, a vertical-scrolling shooter which had more in common gameplay-wise with Namco's own Dragon Spirit than with Bosconian.
Clones of Bosconian include:
- Draconian for the TRS-80 Color Computer by Tom Mix Software, 1984.
- Azarian  for the Atari ST by Synergy Development / David Thomas Stewart, 1987.
- XKobo, 1995, now replaced by Kobo Deluxe.
Dedicated Bosconian arcade machines have become somewhat of a rarity for arcade collectors, because many of them were converted to other, more profitable games over the years. Galaga was the most common conversion choice, because it uses the same basic hardware platform and wiring harness as Bosconian.
Bosconian was the first game to include the now-standard continue screen and timer at the end of a game, giving a player who just lost his/her last life a certain number of seconds to insert more money to continue the game from the same level. The continue feature could also be disabled entirely for arcade owners who did not want it by changing a DIP Switch setting. However, there is some debate over whether Bosconian or Tempest should be credited as the first video game to introduce the concept of continuing. Tempest is the older of the two games, but it did not have a continue screen and timer. Instead, it gave the player a choice of starting levels at the beginning of the game, up to the highest level currently unlocked on the machine. If it was the same player as the previous game, then he/she could opt to "continue" by selecting the same level where the previous game ended. Any future Tempest player was also free to start a new game at the higher level, though, whereas once Bosconian's continue timer expired, the next person to play had no choice but to start over at Level 1.