Well, sure, odd and limited systems can certainly be fun to learn and bring to a usable state. You can play the same game with the PC hardware: it's called the demo scene (e.g. kkkrieger). Usually a different game with that kind of power, though. The game is to do the coolest stuff you can with the hardware. You might squeeze out extra performance, modify the software architecture, leverage components in creative ways, and so on.

You should've had a lot of fun with Cell processor if you like hackery. It blended several different models into one interesting piece of hardware that could be tweaked into emulating them all and doing some side-by-side. More interesting (and useful!) than any of the above systems. That's why supercomputer people put a cluster of them to good use. :)