Descpription:
The game begins by asking the player(s) to choose a difficulty level,
however, instead of making the enemies more difficult or the players
weaker, higher difficulties start the players in a later set of levels
(called "galaxies") and with some powerups.
The easiest difficulty level starts the player(s) in the
first level with no bonuses.
The player controls a tank and must navigate through multiple levels
(14 in the arcade version) from bottom to top, encountering obstacles
and enemies. Along the way, a player may find powerups including tank
fuel, stars (currency), shields, and two types of sub-weapons:
smart shots (homing missiles) and bombs (powerful rockets).
Each level has a key that will open a door at the top of the level,
which will either take the player to the next level or to a special
hub with multiple powerups that must be escaped in 10 seconds or less.
If the player is unable to escape, the tank will be heavily damaged or
destroyed. After escaping the hub, the player(s) then proceeds to the next level.
