Xerix II: The Caverns of Mars

Xerix II: The Caverns of Mars is a side-scrolling shoot-'em up for one or two players that continues the story of the original Xerix. Taking place three years after the events of the first game, the Earth and its colonies are again threatened by hostile aliens, who have built their base in Mars' underground tunnels this time. The player, a skilled experimental spacecraft pilot, is tasked to again take control of the upgraded Xerix ship and, alone or with a wingman, finish this threat once and for all.

The player's ship is flying from the left side of the screen to the right, facing waves of enemy fighters flying in dense formations, as well as stationary turrets of various kinds and boss enemies. Some enemies drop powerups, which either add to the player's score, upgrade weapons or replenish health. In some levels, action is viewed from the above, and in others, from the side, but this has little effect on gameplay.

Xerix II was originally sold as shareware, with the unregistered version limited to six levels out of twelve in the full game. Eventually, author Brendan Reville made the full game freeware. The registered version allows to start a new game from either level 1 or level 7, similar to Apogee model shareware titles (except the episodes are not named here). Users could also separately order the game's complete source code, an offer which appears to have been since discontinued.