Xevious

• At least 4 different prototype versions exist, all with varying degrees of differences with graphics and sounds.  The earliest known version, dated 10-13-83, lacks a title screen and has a purple Solvalou (pictures #1 and #2).  A later version has a title screen, but with a “Namco 1984” copyright date and a blue Solvalou (pictures #3 and #4).  A 11-23-83 version has the correct “Namco 1982” (picture #5). The latest known version, dated 1-4-84, has a different-shaped Solvalou that fires small shots (picture #6). There's also a version with a detailed title screen, but this was done outside of Atari.

• BUG: 8 of the 10 known prototype versions have a serious bug in them that crashes the game.  Of those, 5 will crash after you reach the 2^nd giant bird geoglyph (similar to Peru’s Nazca Lines hummingbird).  The versions that don’t have this bug are dated 10-13-83 and 11-28.