Heiankyo Alien

Heiankyo Alien is an interesting beast, being an early arcade hit that was developed by a small group of college students without much in the way of resources. It's more or less unknown in the west, but a quick glance at some gameplay is enough to show that it's been highly influential on the industry in Japan; it was one of the first maze games, there's a case to be made that we don't get Pac-Man without it.

The premise is a little more complicated than your average arcade game, particularly for the time, but surprisingly easy to get to grips with despite that: You're in a maze, there are some aliens running around (four to start.) You have a shovel, and with one button you can dig a hole in front of you, and with the other you can fill it up. You have to dig 5 times to make a hole of the maximum size, and it takes as many inputs to fill a hole as it took to dig it. You can't walk over holes, but aliens will fall into them and be stuck there for a short time based on how big the hole is. (If another alien runs into a hole with an alien in it, it'll rescue the trapped alien early.) Once an alien is trapped in a max-size hole, you can then fill it back up to bury and kill that alien, and your goal is to do this to every alien on the screen before you hit a time limit (at which point a huge amount of aliens spawn in and the game becomes impossible.)

This is pretty unique, as a player your options come with a lot of start-up time and are heavily dependent on maintaining tight control over your positioning relative to the traps you're laying (because once an alien is in the hole you have a limited time to get there and fill it, and filling it takes just as long as digging it did.) It creates a really unique rhythm of play where you're kind of always on the back foot, since aliens kill you instantly by running into you and move pretty fast.

Unfortunately I think the game does ultimately butt up against the limitations of computing in 1975; as far as I can tell there's no way to predict alien behavior, they seem to just run around at complete random, and this doesn't really gel all that well with a mechanical setup where your only method of offense is laying traps for them to run into. At the end of the day, no matter how well you strategize your trap-laying, it's just random chance whether the aliens actually fall into them or not, and as a result it didn't take me a huge amount of time to lose interest. There's charm here for sure and with some slightly more robust enemy AI I could see this being a rollicking good time, but it does unavoidably fall short of what feels like its true potential.