Clue for the clueless ones:
1) If you don't code, don't give advice. It's most likely wrong.
2) Amiga DOES make it possible. Get a clue:
http://www.pouet.net/prod.php?which=25778and for the lazy:
http://video.google.com/videoplay?docid=-7395031487060167101ftp://ftp.untergrund.net/users/hellfire/tbl-starstruck-2006.aviftp://ftp.untergrund.net/users/acryd/videos/tbl-starstruck.mpgYou can do almost everything you can do on a modern PC (for Sims type games), bar advanced T&L hardware support (vertex/pixel shaders), HDR, etc, and of course advanced sound (3D). It just takes some (or plenty) smarts.
But Sims, AFAIK, doesn't need all that.
3) Clue: as far as code portability and "Amiga quirks", etc, EVERY system has quirks. Speaking of Windows, if you've ever programmed it, it's the king of quirks. Because it's convoluted and has TONS of dead weight.
But furthermore and MOST importantly: WELL WRITTEN CODE IS PORTABLE. PERIOD.
Ask any good programmer. He'll tell you the same. Look at SDL code. Look at id software code (Quake1 and up). As Piru mentioned, Quake3 was ported in a very short amount of time.
4) Finally, the guy himself WANTS to code for the Amiga, so I don't see why the hell some people are suggesting other platforms.
But if we're to suggest, then here's my suggestion Starfoxx guy: Objective-C and Cocoa and OpenGL, using Xcode and InterfaceBuilder on a Mac. Hands down the best object oriented programming environment (my opinion, but then again many people in the past have stated so, including John Carmack and John Romero of id software, you know Doom, Quake, etc. All those were initially coded under the NeXTStep environment using Objective-C, C and NS (ex-Cocoa)). To understand how powerful it is, you have to see it, but here's an example of making your own FULL web browser with 0 lines of code:
http://www.macdevcenter.com/pub/a/mac/2004/01/23/webkit.html The only caveats with Cocoa is that it doesn't exist on Windoze or Amiga (give me enough time, or hope GNUStep is fully ported).
In general, fsck Windows. It's short-sighted and closed. It's a trap. You will stop learning really quick, and learn following (what M$ says). But it will offer your paying jobs, and plenty, unfortunately. So YOU decide, how to sell your soul...
Seriously now and back to the Amiga part of the issue, you should follow what other people suggested about playing around with AMOS and AmigaBlitz. You have to learn to crawl (because from what you said, you're not even crawling when it comes to code development), before you can get up, before you can walk, and then before you can run. And after that comes SPRINTING. And that's what game development is. For those not in the know, game development is one of the most rigorous fields of programming because it involves programming, interfacing and synchronizing multiple very complicated subsystems. When you program games you have to deal with: IO hardware, disks and files, graphics and sound, timing, synchronization, memory management, even threading/locking and race conditions (if you're want to support many of the modern multi-core CPUs and GPUs), etc. It's not like writing a word processor.
Anyways, good luck in your endeavour, but take it slow, a step at a time, with small and realistic goals. It's do-able, but only if done with the right approach just mentioned.
