There are many Amiga games converted back in the day to Risc OS.
Zool (32bit version) works natively on Risc OS Pi, among others. Not compatible games are being fixed. See full list here:
http://www.acornarcade.com/forums/viewthread.php?threadid=11999&page=1#121577
!!!! Update to latest development Risc OS ROM. The Risc OS ROM that comes with the default distro is outdated and has keyboard issues that will lock up the games.
Latest ROM can be downloaded at the developers site here:
https://www.riscosopen.org/content/downloads/other-zipfiles
NOTE: Risc OS ROM is open source and free. Risc OS scene is not plagued by bad born bastards who steal money from old OSes, like the sad Amiga scene.
Risc OS also has cheap and solid hardware with a VERY GOOD price/feature ratio, not like the lame OS4/MOS hardware situation.
This is very interesting for me - I have a Raspberry Pi too and had basically given up on it because the Linux OS included with it is not my cup of tea to be honest. I was even planning to give away the Pi as a Xmas present this year!
The Risc OS build for Raspberry Pi you mention sounds very interesting and I have decided now to keep the Pi a bit longer to try it out! I have never used RiscOS before! I have ordered (donated) to get my SD Card with RiscOS pre-installed and look forward to trying it out soon!
Thanks for showing me something that makes it worth keeping the Pi for! :-)
Catcha,
Epsilon