Re: Minecraft won't run in 10.10 PPC
My understanding is that the official Java doesn't work on Linux for PowerPC, and Minecraft doesn't work on any unofficial Java implementations. That would be your main problem there and I can't think of any way of working around it.
I try to treat the cause, not the symptom. I avoid the terminal in instructions, unless it's easier or necessary. My instructions will work within the Ubuntu system, instead of breaking or subverting it. Those are the three guarantees to the helpee.