One of the most famous 'lost' Atari 7800 prototypes, Sirius was known to be in possession of a long time collector but was never released to the public. The reason for this was that the prototype was very unstable and would crash frequently. This was due to the fact that Sirius needed to be run from an Atari 7800 developers kit, and would not run on a stock Atari 7800. However in 2008 the source files for Sirius were found on a hard drive, and due to the efforts of some very talented individuals, the game was patched so it could played on any Atari 7800.
Sirius is a horizontally oriented space shooter that plays along the same lines as Gradius and R-Type. There are four different levels, each with its own unique theme and boss. Unlike its sister game Plutos, Sirius is one player only. The difficulty level can be controlled by the left difficulty switch, but all this really does is make a hard game harder.
Sirius offers two different kinds of upgrade capsules, a Remote Ship upgrade and a Weapons Upgrade The remote ship upgrade is similar to the Option from Gradius in that it is a little ship that follows you around and fires at enemies. The second type of upgrade increases the firepower of your weapons (which is desperately needed in this game). There are two different weapons upgrades available: Rapid Fire and Spread Fire. Upgrading your weapons is the key to staying alive in Sirius. There are also small diamonds scattered about the levels that give you a few bonus points when collected.
As previously mentioned, there are four different levels in Sirius.
This level takes place in an asteroid field. Although this is the first level, the difficulty starts high and goes up from there. Make sure to watch out for the tiny bits of rock scattered around the level as crashing into these is deadly. The boss of this level are two ships with lasers.
This level appears to take place in a futuristic looking space station. Watch out out for ground turrets and pathways that branch out in different directions. The boss of this level is a large stationary alien that is similar in appearance to the first boss from R-Type.
This visually uninteresting level appears to take place inside some king of organic environment. New twists include barrier walls that must be carefully navigated and spitting alien plants. The boss of this level is a large eye shaped organism in a protective case that spits large spores at you.
This level appears to take place inside of some ancient ruins. Out of all the levels, this one is the most graphically interesting (not to mention the most challenging). The boss of this level is a large crab shaped ship with a large crystal in its forehead.
Sirius is an amazing feat of programming and it measures up quite well against NES and SMS games of the same time period. Sirius shows what the 7800 was capable of if properly programmed. The only flaw with Sirius is that the game is unforgivably difficult, and may prove to be too much of a challenge for all but the most seasoned space jockeys. Sirius looks complete, but lacks an ending which may point to the fact that there was still more work to be done.
It's a mystery as to why Sirius was never released. Tynesoft was well known developer of Atari 8-bit and ST games in the UK, but was relatively unknown in the US. It appears that they were trying to break into the Atari 7800 market with Sirius and its sister game Plutos (another space themed shooter), but left the game industry before either could be released. It's a shame that Atari didn't pick these games up, as they make a wonderful addition to the Atari 7800 library.