This release is pretty old but worth to be mentioned. “Lode Runner” is a free and open Source ‘Lode Runner’ game for Mobile Phones (J2ME MIDlet).

Features:

Clone of the original Apple II version Both ‘LodeRunner’ and ‘LoderRunner Championship’ versions are supported (300 levels total)
Source is heavily commented
Tested with Nokia phone MIDP 2.0 (should be easily portable to MIDP 1.0)

http://code.google.com/p/loderunner/