itch.io

Thanks! 

I made a diagram showing exactly how the title screen works: https://geminorons.neocities.org/wiaf/#figC

Basically, it's using a single four-colour palette for the whole screen, but the colours in the palette get updated as the screen is rendering. So the art uses one colour for the background and one for the logo text, but you end up seeing two vertical gradients on screen.

No, it only works on Game Boy Color (and later compatible consoles). It won't work on earlier models like the original Game Boy, Game Boy Pocket, Game Boy Light, or Super Game Boy.

There's actually a web version, but it doesn't seem to display in the itch.io app.

If you visit the game page through the itch.io website, you can play the full game for free in your browser.

https://gearfo.itch.io/geminorons

No, the only game mode is player vs. CPU. The HTML5 version on the web has all the same features as the .gbc ROM file.