The Archimedes had a better CPU, which enabled better graphics. But I never used an Amiga, so I don't know if the videos on YouTube are at the real resolution.
(For those unaware: this is Acorn as in Acorn RISC Machines, an earlier name of Advanced RISC Machines, i.e. ARM.)
The Raspberry Pi capably runs the RISC OS operating system natively on its ARM processor, in many ways it could be considered to be the spiritual successor of the Archimedes.
I know the hardware has changed in ways that trip up games, so it's not a guarantee that Lemmings would work. I found some information here: https://www.raspberrypi.org/forums/viewtopic.php?t=32036&p=2...
It's from the "Archimedes Software Preservation Project" [2]. I must get in touch, since a few years ago I imaged most of my Acorn floppy discs, but I haven't done much with them. If the Raspberry Pi makes it very easy, that's great.
I'm very pleased :-D
[0] http://forums.jaspp.org.uk:9000/forum/viewtopic.php?f=25&t=9...
[1] https://www.riscosopen.org/content/downloads/raspberry-pi
[2] http://forums.jaspp.org.uk:9000/forum/viewtopic.php?f=14&t=3... and http://forums.jaspp.org.uk:9000/forum/viewtopic.php?f=9&t=31...
[3] https://www.raspberrypi.org/forums/viewtopic.php?f=91&t=1401...
Anyone going to school in the UK during the 90s will probably have encountered an Acorn.