So if you wanna play duke nukem. http://www.darkmystics.com/g1 is where to go. You have to put the file on your SD card in the doom folder. (I used Lind file manager) However.. was odd tho, Do not try clicking it with the G1 browser.. seems to wanna load up as a txt file which then freezes the G1. Instead long press, save link as, then after it saves, use lind to rename it to .wad and move it to the doom folder.
Download Doom on the Market, its free. Then install sounds, install the various wad files you want, long as this wad file is in the folder it works. One glitch however. It wont use the Duke 3d sfx. So Id suggest turning them off. Since its mapping Doom sounds to Duke3d but if you wanna play Duke, least its something. =) Just wanting to give back something to the forums. (Since on the market the other dev charges for Duke Nukem..)
Anyways hope this is ok with everyone and hope you have fun. =)
Update: Went more digging in my files. Heretic works as well now. =D
Sadly my Quake 2 doesnt.. nor counter-strike. But I am still working to find what more I can add for you all. =)