Yeti3D is a well known 3D engine. Lineus picked up the work on the existing GP2x port and improved it.

Release notes:

I am now, what, the 5th generation maintainer of this code?
Anyways, I took synkr0’s port and pretty much just tweaked a couple of things, like
the “keyboard” structure, remapped the controls, got rid of that annoying SDL cursor,
and added some SERIOUS optimizations — It runs just fine at over full speed with the
2x underclocked to 130 MHz on my setup at least. I even managed to shrink the
executable – I’m a whole 10kb under synkr0’s file! The makefile I used is Makefile –
synkr0’s has been renamed to Makefile-synkr0.

Controls are now:
Joystick – move
Start – exit
Y – look up
X – look down
A – fire
B – jump

NOTE: exit does not call the menu to start again, so you’ll have to either write a script
or use the wonderful gmenu2x’s wrapper feature.

Next step – fix minor bugs and do a complete re-haul. This is gonna be fun.,0,0,0,46,2458