Idea replies — I’m building a handheld retro gaming device. Who’d like to design the case with me?

There's actually someone here on CoSell who makes 3D models in Blender and is looking for projects. That might be a useful conversation to start! Beyond the enclosure, have you considered designing it so the case can be printed and replaced at home? Different colours, grip sizes or button layouts could make it much more interesting to hobbyists than a single fixed design