There are some titles from Ambrosia Software that I really miss, and wish could be had on an Intel mac running 10. Mars Rising, Maelstrom, Barrack, and EV Override were some of my favorites from OS9 days. Now on the rare occasion I get a hankering for a video game, I just go down and use my son's Xbox or Wii.
There was a
legitimately sanctioned GPL'ed copy of Maelstrom for various O.S. platforms, including OSX. The original site appears to be down but
you can download prebuilt binaries of the game here. Parts of the mirror site appear to be broken so I can't find the source code and GPL license that are supposed to be included with it there. It appears there's an RPM file for linux
you can possibly extract the original source from
here and though I'm not completely sure, I'm of the strong persuasion it was originally licensed under version
2.0 of the GPL. When I can, I'll check to see if I have everything bundled on the HDD of my old, broken computer later to be sure.
If it's of any consolidation Escape Velocity: Override also lives on via a Port Authority Total Conversion for Escape Velocity Nova available as an Add-on at Ambrosia's site, albeit you need to register Nova and P.A. isn't a direct 1:1 port thanks to differences in the Nova engine.
Also just to remain on topic, a list of other natively compatible games I recall playing on my 2008 24" 2.8gzh iMac at some point before it (physically) crashed, alongside some notes:
PacTheManX
Escape Velocity Nova
Braid (Wonderful time manipulation 2D platformer with puzzles)
Neverball
Aquaria (Plays beautifully with an arcade style joystick, if you get the hang of tricking out the diagonals.)
Mechanarium
Penumbera Overature
Frozen Bubble
Osmos
Samorost 2
Cortex Command (The controls were way too finicky for my tastes though)
Portal (Valve SteamGiveaway Edition)
The Battle for Wesnoth (An earlier work done in large part by some of the Frogatto people)
Frogotto
Demios Rising
World of Goo
Lagaru HD
Cave Story
Unreal Tournament 2004
Sketchfighter 3000
There are probably lots more but I can't think of them for the life of me at the moment.