Thanks for your answer. And how about a SGB game that would use SGB only features? (like colors, SNES sounds, multiplayer, etc.)
There is some untapped potential in this accessory IMHO, as most commercial SGB games didn't rely on the SGB-only features to be able to work on a GB too. But I've been tempted to make "SGB-only" game for quite some time, that compo would be a good opportunity to finally try my hand at such a project if it's not against the rules?
In the gameplay idea I have in mind, the code will mostly run on the SGB CPU indeed, but the input, and audio and graphical output will be SNES related. I know it's kind of a stretch, but I see it quite similar to using a SA-1 chip or SuperFX chip, which the compo rules allows. And the fact to use an accessory like the SGB is tied to the "perspectives" theme :).
How about making a game for the Life Fitness bike? I need to get back in shape!
On a more serious note, even though I can't answer the question conclusively, the rules state that SNES-era expansion chips are allowed.
I think SGB, scope, mouse etc. can be considered to be period-correct expansion devices, they're not explicitly forbidden and should therefore be permitted.
However, you might needlessly limit your audience by mandating non-standard input devices.
After the jam has ended, players will typically try the released games in quick succession.
A game that burdens players with additional configuration or can't be played on real hardware if they lack the required device might be a turn-off.
Regarding SGB games:
If it's a SNES game packaged inside a GB ROM with the corresponding SGB loader and you release a pure SNES ROM version alongside the GB version (which should be a relatively easy thing to do), I don't see a way to object that.
If it's a GB game that only runs on the SGB, I feel that's a bit of a stretch.
Just my two cents, though.
Hi, I see things in a similar way, and think that a "SGB only" game should be allowed by the current rule as it's now clearly forbidden.
My intent is to make a SGB only game, that mainly run on the SGB and not a SNES Rom embedded in the SGB. I want to try to use the SGB feature regarding display (colors, the fact that you can display part of the border over the gameplay area, etc.) and audio (the library of embedded sound and audio engine) in a unique way, in a way that no commercial game did it during the 90's. A GB cart that can't be played on a GB would make no commercial sense then, but for such a retro development I think it could be a cool project :).
But I wanted to ask if it was OK before going too far in the project, and I can see that not everyone is ok with this "edge cas". I hope we can have an official answer from the compo organizer to see if it's ok or not.
Regarding accessibility, I actually though of it too, and I think requiring a SGB is less an issue than requiring a SNES mouse or a Super Scope. For one, the SGB is perfectly emulated in the latest versions of BSNES and Higan. And for real hardware, if you don't have SGB + GB flashcart, you can actually play the game directly on the SNES with a SD2SNES / FXPAK Flashcart, as it have a SGB core now :).
