For gaming, why not just run the PC-versions of Dune, Monkey Island and Settlers? They aren't exactly the same but is the difference really that important?
One reason is that back then, many DOS versions of games only had AdLib or even just PC speaker support, while the Amiga version came with fully digitized audio.
Compare https://www.youtube.com/watch?... to https://www.youtube.com/watch?... , https://www.youtube.com/watch?... . (The sound is actually in stereo, but the Youtube videos are downmixed for some reason.) The difference can be jarring thanks to the inferior music.
As a matter of fact, the Amiga was famous for its sound (and graphics) capabilities back then, *especially* compared to DOS. (Well, until 256-color VGA became common..)
Some DOS games had digitized audio as well, but Amiga could mix 4 channels in hardware. Mixing had to be done in software in DOS, unless you had something like a GUS or an AWE32 sound card.