I'm tinkering with a voxel space rendering tech demo as a PlayStation homebrew. After one weekend of work I'm getting decent results (like, 10-15 FPS) and I've yet to use the DMA, the GTE or even polylines primitives.

It's refreshing to dust up trigonometry and good old low-level optimization tricks. When the scratchbuffer has 1 KiB and the stack can only use a fraction of that, it makes me realize how spoiled I'm at work with the microcontrollers we have, with threads being allocated 8 KiB of stack and backtraces with over 50 functions of C++ templates on it.