Trying to create a game which is able to cross-compile natively to both modern platforms and retro consoles will likely be futile. Some frameworks and game engines I know which can create PC games might be able to target current generation consoles, but I could not name a single one which implements support for old legacy consoles. Legacy consoles often have very specialized and unique hardware which requires specialized and unique programming methods to utilize.

The most promising approach would be to develop it as a classic game ROM, but then bundle it with an open source emulator for relase on modern platforms. That's actually not that uncommon. You can find most of SEGA's old Mega Drive game library on Steam which runs that way. Most of Nintendo's old catalog found on the Virtual Console service is also taking that route.

But keep in mind that the legal situation of emulators is a bit shaky. Some console manufacturers feel that 3rd party emulators violate their intellectual property rights, even if the whole implementation of their technology was made from scratch. So just because SEGA puts their old console games on Steam with an emulator doesn't mean they will allow you to do the same thing.

Another interesting route I have seen taken a few times is to [create a cartridge which fits into a vintage console but actually contains a modern system-on-a-chip][1]. The whole game runs on the cartridge. The vintage game system doesn't do anything but supply power and controller input signals and deliver the audio and video output to the TV set. But you can hardly claim that you actually created a homebrewed vintage console game when it requires modern hardware to run and degrades the vintage hardware to a glorified cable adapter. 


 [1]: https://kotaku.com/programmer-hacks-cartridge-to-run-snes-games-on-the-nes-1826434092