ZX Spectrum 48k emulator has been ported by Shiru for ESPboy project.
The ZX Spectrum is a famous 8-bit personal home computer released in the United Kingdom in 1982 by Sinclair Research, was successful worldwide, selling more than 5 million units during its lifetime. https://en.wikipedia.org/wiki/ZX_Spectrum#Software
Thousands of excellent games you can find in the net, the retro heritage these days:
- and modern http://www.retrosouls.net/?page_id=848