I got PALMGB to run smoothly on the epods -- they have a trial version limited to 2 minutes of play on the unregistered version. Gameboy Roms are pretty plentiful over the net. Using an external keyboard make controls a lot more friendly -- I bet a USB gamepad would work even better if it is compatible.
Also, PocketDos (http://www.pocketdos.com/) has a demo version of their Windows CE MSDOS emulator, unfortunately the demo version for Windows CE for H/PC 2.12 or higher is by request only. I did request it, so we'll see if it works, but if it does that means DOS apps would run!