Set on a scrolling starfield, your mission in Bosconian is to destroy the enemy bases to advance to the next level. You must also avoid or destroy the enemy starships, asteroids and space mines.
You are able to move in 8 directions and you can fire both in front and behind yourself at the same time. This means you can destroy objects by both moving towards them and by moving away from them. Your ship is also equipped with a radar scanner which shows the position of bases (green), yourself (black) and enemy ship formations (red). Your alert status is also shown on screen, changing to red when enemy formations are attacking. There are also audible warnings and speech to inform you about what is going on.
The playfield wraps around at the edges, so if you move off the left you reappear at the right side of the screen etc. The enemy bases are scattered across the gameplay arena, protected by deadly space mines and asteroids. The enemy bases consist of 8 gun turrets which fire missiles at you which must be avoided or destroyed and a central reactor core.
To destroy the bases you must either knock out all 6 gun turrets or blow up the central core. The core is protected by a shield which opens and closes, and shots can only enter the core when the shield is open. Also on later levels the central core is equipped with a missile launcher which fires missiles out at you, making it harder to destroy the core.
There are several types of enemy ships whch pursue you intent on your destruction. Occasionally several ships will attack together in formation and if you destroy them all you earn bonus points.
The level is cleared when all enemy bases are destroyed, and subsequent stages have more bases to destroy, more numerous and faster alien ships attacking you and a higher concentration of mines and asteroids to negotiate. The bases are also equipped with better weapons making them harder to destroy.
You start the game with 3 lives, and extra lives are awarded at 10,000 points, 50,000 and every further 50,000 points.
Extra Ships stop getting awarded at 2,000,000 points, giving you a total maximum of 42 ships.
Space Mine: 20 points.
I-Type (Pink) Enemy Ship: 50 points.
P-Type (Boomerang) Enemy Ship: 60 points.
E-Type (Thin Red) Enemy Ship: 70 points.
Yellow Enemy Ship Bonus: up to 800 points.
Formation Bonus: 1,000 points.
Formation Bonus (later levels): 1,500 points.
Gun Turret: 200 points.
Destroying Enemy Base: 1,500 points.
Where possible, destroy the bases by knocking out all the gun placments, as you score more points overall than simply blowing up the central core.
Enemy ships are particularly vulnerable to diagonal shots, and since they turn slower than you, pick them off by running away, making small course adjustments to keep them behind you, thereby destroying them with your rear gun.
On later stages when the base cores fire missiles at you, note that the missiles can be destroyed, and you can fire faster than they can reload. Fly towards the core, destroy the missile, and keep firing to blow up the core.
To Avoid getting "Condition Red", make sure you ALWAYS shoot the yellow ship when it appears on screen. Also, don't take too long in a level or else it'll just turn to "Condition Red" automatically. [JoeyL21988]
If you do get "Condition Red", try to always make your ship's direction in any of the diagonal corners. Try not to go up/left/right/down unless you are trying to shoot at 1 or more of the 6 cannons or the center of the Base. [JoeyL21988]
Whenever you are trying to shoot at the center of the Base in the later stages, shoot the two cannons (one on left and one on right nearest centre side you are shooting on) to make it easier to shoot the center. You don't need to be wasting time trying to avoid the shots, ships, and trying to shoot the center in the later levels.. [JoeyL21988]
On later levels (15+) you will get "Condition Red" more than before. When you are trying to shoot at the cannons/center of the base, and there are bullets and many ships coming at you, back off, and try to shoot some of the Cannons and ships before going back to blow up the Base. [JoeyL21988]
On any level, try to go in circles to ward off ships as if you are going up and they are going down, they will go off screen :) [JoeyL21988]
After level 20 or so you will see levels that you have been playing before. [JoeyL21988]
Try to figure out patterns for certain levels, meaning the order in which to the destroy the bases. Sometimes it's easier to shoot just one side of them, such as when they are all in a single line horizontally going across the screen, then change sides and you'll have more work accomplished in less time. [JoeyL21988]