Wow they are not cheap, go my raspberry Pi3 for £35, downloaded an img to a micro SD, bit fiddly sorting out some controls but once done it's great. Perfect for anything 16bit or earlier, struggles sometimes with N64 or later console and higher end arcade. Ideally I'd love to set hyperspin up on my nvidea shield, tried before but that was a right ballache, need to spend some time and try again as that'll play everything available.