With the priority changes in lordgun.c, and the graphics roms dumped, Alien Challenge is now playable, also thanks to the protection patches sent by XingXing:
































This was the first combat game by IGS. Screen shots are from the World version, even though most text is in Chinese anyway.

The Chinese version (currently in MAME as Huang Fei Hong) is partly dumped. It shares the sound program and samples roms, has an earlier revision of the program roms and lacks a dump of the graphics. By overlaying the upper part of the World version program roms, and by providing its own protection patches, it boots. The only difference I can see, using the graphics ROMs from the World version, is the program revision in test mode and the boot screen (it even shows the FBI logo). At any rate, I'll mark those program roms as bad dump (half size).

The game uses a multi-sprite mode that was previously unimplemented, and also shows that the sprite-list-end handling in the driver was wrong. The missing background music still needs fixing.


Source: www.lucaelia.com/mame.php