Curiosities Vol. 2 - Mini Vaders and Dottori Kun

These two games are by different companies (Mini Vaders by Taito, and Dottori Kun by Sega), and are in different genres. They do have things in common, though: they share an incredibly minimalist aesthetic, with no colours, no sounds and very simple sprites, and though they look like they're early experiments into videogames from the 1970s, they were both actually made and released in the early 1990s.

The story behind this is that they're both games made as cheaply and simply as possible, with the purpose of being packaged with JAMMA arcade cabinets. There are two stories floating around the internet as to why these games exist: the first is they exist to ensure that the cabinets are functional, and the other is that there was a Japanese law at the time that required that all arcade cabinets be sold with games installed. I don't know which is true, but the legislation story seems the most plausible, since neither game appears to have any kind of test functions.

Mini Vaders is the best (or at least, the most interesting) of the two games, being a very simplified Space Invaders variant, with no score and no lives, but a somewhat unique design. Each stage consists of a formation of invaders that don't shoot at the player, but they do advance down the screen very quickly, and it's up to the player to shoot them before they do. It goes by the classic Space Invaders rule of allowing only one of the player's shots on-screen at a time, and due to the fast pace of the invaders, missing a single shot can mean death.

Dottori Kun is not so interesting. The game is a simple dot-collecting maze game, with the player controlling a V and avoiding a CPU-controlled X. When the screen is cleared of dots, it refills and the players score increases by one. The player can increase their speed by holding the fire button. That's it for Dottori Kun. I guess it doesn't really matter though, since neither game was made to actually be played by anyone.