Heiankyo Alien (GB)

In Heiankyo Alien, players assume the role of a Keibiishi (imperial guard) tasked with defending the ancient capital of Heiankyo from an invasion of fearsome aliens. The game takes place on a single screen, depicting a maze-like area where aliens move freely.

The core gameplay mechanic revolves around digging and filling holes. Players can dig a hole by pressing the A button when standing on an empty tile. When an alien steps onto a tile with a hole, they will fall in and become trapped. At this point, the player must quickly fill that hole by pressing the B button to eliminate the enemy. If not filled in time, the alien will eventually crawl out of the hole after a certain period.

The challenge of the game lies in the player's ability to move skillfully to avoid direct contact with the aliens (which results in losing a life), while simultaneously calculating the optimal positions and timings for digging and filling holes. As the number of aliens increases and their movement speed accelerates, controlling the map and trapping them becomes significantly more difficult. The objective of each stage is to eliminate all aliens on screen to advance to the next. Heiankyo Alien is a classic example of the 'trap 'em up' genre, demanding strategic thinking and quick reflexes from the player.