Zanac is a Nintendo Entertainment System video game released in 1986. It is seen through a bird's eye view, 3rd person perspective. The shoot 'em up video game was later rereleased years later in 2007 on the Wii's Virtual Console.
In the game, the player controls a ship made by 256 people that was created as man's last hope against an army of alien creatures. In all there are 12 distinct stages, and the goal is to get through each one until you ultimately reach the final level in which you'll have to raid the homebase of the aliens. Each location is assumed to be a different planet, suggesting that the game takes place far in the future.
Interestingly, the game's A.I. will improve, or become harder, based on how you are playing. If you're doing a shoddy job, then the game will be easier for you, though if you're blasting through the enemies without taking any blows, then the enemies will become harder.
At the end of each level will inevitably be a boss fight. Boss fights always consists of a primary core that the player will have to destroy in order to defeat, and commonly you'll find turrets that'll fire at you during the entire fight. Each boss has a set time, and you'll have to defeat him in order to progress to the next stage.
The Virtual Console version of the game received a medicore score of 7.5 from GameSpot, while Hardcore Gaming 101 surprisingly gave the original a 10/10. So far the game has not only been released on the NES and Virtual Console, though also on the MSX and Palm OS, albeit the latter two versions weren't nearly as successful as the NES title.