Glad I Downloaded This It took me roughly a day & a half to get to grips with this emulator and how it's all configured etc  but it's worth the perseverance. I had the same issues with the annoying bios message prompt  when I'd already placed them in the correct directory. Solution: On your device - Settings &gt; Apps &gt; Clear Data + (cache) for Reicast. Worked there after for me. Also  check out the Reicast Wiki page  tells you all you need to know. Skies of Arcadia will work  but in .GDI format only! Hope for near future updates 👍
June 20 2016