Lots of questions :) Were you working in the space at the time?
> Was your Treo also a Windows Mobile device or the PalmOS version?
I'd given up on Palm long before they switched to WinMo. But it that was computing history repeating itself, where previously Apple's problems with System 7 led to the consideration of BeOS, Solaris, and eventually the acquisition of NeXT.
> Didn't RIM perfect the convergence of PDA and phone or did Blackberries have their own issues?
Blackberries were perfect as messaging devices. The carriers had a special class of messaging devices to be sold to customers who wanted hardware qwerty keyboards. Blackberries were definitely best-in-class of that category.
But it was simply a different story once there was a phone with a near desktop-class browser, not to mention a GPU, and a pre-emptive OS with memory-protection, whose system developers who had years of experience with a similar OS. The phone manufacturers were simply out-classed. It doesn't surprise me that Google was the one to step up (or, well, the Danger/Android guys), because you had to have that kind of expertise to match Apple. Even then, it took Google until about 2012-2013 before Android was nearly on-par with iPhone. When Jobs said Apple had a 5 year lead on everyone else, he nailed it.
> Were those proprietary OSs a form of *nix, TRON, or something else entirely? I thought Motorola's RAZR phones, like the Sony Ericssons, licensed Symbian from Nokia, but I could be mistaken.
No idea about the proprietary OSes. The early RAZR always struck me as a digital form of the analog StarTac. It was amazingly thin, but not great for anything else. It looks like there was a Linux version [1]. And you're right, in 2009 there was a Symbian/UIQ version [2].
> How deep into the hardware were you when you were building games for those platforms (e.g. ARM asm, special undocumented microcode, etc.)?
Not at all. You could code in assembly for BREW, and some game developers I knew did that for a few inner loop routines, but I never bothered. As far as access to phone internals, you pretty much needed a special relationship with the manufacturers. The game publishers I worked for did get pre-loads on phones, and sometimes that did require some hardware-specific work. Once when Nokia was attempting to make CDMA phones, we got preloads on one of their phones and I found out that their version of the OS had no way to relocate memory so everything had to be pre-allocated a special way. Before I worked for the game publishers, I worked on MobiTV's BREW client and they got some kind of preload deal with Qualcomm, which led to me getting access to their hardware video decoder, but it had an API. It was a little annoying because it wasn't designed for streaming, so the entire chunk of video had to be fully downloaded before it would play.
> Were gaming phones like the N-Gage or Xperia any better than their purely mobile counterparts in coding or feature-set?
Yes, but we never made special games for them. The N-Gage could run J2ME, and so we just ported J2ME games to it, even pre-loads.
> While you had those Japanese phones in your hand, did you try iMode or play any games on them? Any models that were notable to you in '99? Any features you were hoping would make it stateside?
Honestly I had a hard time understanding what I was looking at. One friend had one that looked more like a short colorful ruler than a phone. She hung it from her purse with trinkets hanging off of it. At the time ('98-2000) I was living in Sāo Paulo, consulting for BCP Telecomunicações (now Claro Brasil) on one of the largest cellular deployments of its time (later to be dwarfed by ones in China and India), and the phones in Japan were utterly different from anything in Brazil or the US. Japanese phone culture was so alien at the time, the way people accessorized them and messaged each other. Emojis didn't exist elsewhere.
> Did you ever work on older mobile systems like the Apple Newton, EPOC32, and GEOS/Palmtop PCs?
Nope. I mostly worked on PC games during the 90's. I did have an Apple Newton though. I think I might still have it, somewhere in a box in storage.
[1] https://en.wikipedia.org/wiki/Motorola_Razr2
[2] https://en.wikipedia.org/wiki/Motorola_Razr3