Game Boy cart converts handheld into a wireless controller

[HEXUS]

Cart is compatible with Game Boy, Game Boy Colour, Game Boy Advance / SP consoles.

Read more.

[Output]

It's great to see people making things like this, extending the abilities of older hardware.

It's not something I'd be likely to use myself though.

[Ttaskmaster]

I thought someone had already done one of these for the GBA and GBC... BennVenn, perhaps?
Would be really cool if the handheld could receive back and display additional info on its own screen, too!

[DevDrake]

mehh, its using custom receiver. I was expecting to see wifi or bluetooth from the get go.