Hi Jamie,
I'm sad no-one's posted on this. I am the proud owner of Qwak on Amiga... Great little game!
I think the Mac market is really worthwhile, due to there being less competition I hear there are better conversion rates on portals and such... But it kinda depends on how the title did on other formats for you.
I also wrote a cross-platform Bubble Bobble-inspired game,
Super Neko World. It also started life on the Amiga.
It's something I'd like to see more of but platformers are just so hit and miss in sales these days due to there being so many great freeware titles, and competition on the consoles, especially now with the 'Indie' tier of things like PSN, XBLA and WiiWare. I think it might help if you made it Qwak 2 and introduced some new mechanics that sets it apart from others. Either way, I feel you had a great knack for fun gameplay which I'd love to see in some new work.
Hope all goes well,
Cheers for the fruit-nomming!
Jasper.