"The stunning shoot' em up epic which hurls you into the deepest regions of viscious Delta space and the fight for your life!"
Delta is a side-scrolling shoot-em-up which was released on the Commodore 64 in 1987. It was created by Stavros Fasoulas, famous for Sanxion and Quedex (which were also developed for the C64). The game features SID music by the musical genius, Rob Hubbard. It was originally published by Thalamus (of Creatures and Hawkeye fame). Delta was later re-released as part of Thalamus' 'The Hits 1986-1988' bundle.
"Screens and screens of death-dealing destruction and mayhem."
The story focuses around the plight of the Terran Empire, who's lives are being threatened by the Hsiffies, "nasty yellow, buck-toothed, slimy aliens, who cheat at poker, mistreat their mothers and jump red lights", as described by the manual. In an effort to deter the threat, an elite squadron named DAMOCLES has been reformed, and as a member of the group, it's your job to obliterate as much of the Hsiffan attack fleet as possible.

The game takes place over 32 levels, and you have the opportunity to upgrade your weapons along the way - destroy a whole attack formation, collect credits, and pick up weapon icons which you can afford, depending on the number of credits you have. Weapon upgrades include more bullets, multiple fire, and the interestingly named 'Fish Weapon' (or 'pulse-lasers', to the layman). Featuring some obligatory parallax scrolling, Delta is a reasonably pretty game, and is also a good challenge to shoot-em-up fans (but maybe a bit frustrating and difficult for anyone else).

A sequel called Armalyte was created by Cyberdyne Systems, which is regarded as the better of the two games.