Run MorphOS binaries on AROS/PPC (hosted on Linux/PPC; if existing at that time already, hosted on Mac OS X/PPC and native AROS/PPC as well).
To do so, all system structures and public structures of AROS have to be properly aligned with 68k alignment rules - the compatibility would not be perfect, because of some differences between the different operating systems, but that could be wrapped or emulated by a kind of -mosemu-.
To prove sufficient compatibility, the MorphOS versions of Soliton and MPlayer have to run on AROS/PPC.
Soliton is a fairly old Amiga game which uses MUI; it does not use the latest tricks, but the emulation must have working BOOPSI. MPlayer needs asyncio and lowlevel I/O; furthermore, MPlayer is Altivec accelerated and uses lowlevel graphics calls to CGX. Furthermore, the MorphOS application os4emu has to work on AROS/PPC, running FPSE; FPSE uses a fairly good amount of lowlevel libraries and device calls.