|This article or section is incomplete. It doesn't have all of the necessary core information on this topic. Please help the SRB2 Wiki bythis article.|
Through SRB2's development, several releases, or versions, were made. A major version contained a multitude of improvements over the last version, such as changes of the game engine or the addition of new levels. Minor versions usually consisted of bug fixes and smaller additions. The below is a general list of major versions. Minor version are lumped together with the major version they belong to.
These releases of SRB2 precede the first actual demo of the game. They were similar to a tech demo, as they didn't include any of the current levels and were mainly used to show off the state of the game engine and expand on it.
SRB2 TGF was the first version of SRB2. Unlike the current incarnation, it was a 2D game created in The Games Factory, like its predecessor. The idea was discontinued when SRB2 was moved to the Doom engine in 1998.
SRB2 Halloween was the first SRB2 version made on the Doom engine. It consisted of one Halloween-styled level showcasing basic elements of Sonic gameplay.
The successor to SRB2 Halloween, SRB2 Christmas, included several levels and had a Christmas theme. Five versions were released between late 1999 and early 2000, each progressively expanding on the game's engine to make it more Sonic-styled.
These demo versions started to add actual SRB2 levels that should end up in the final game. They also expanded on the engine and introduced the concept of netplay, as well as other substantial game elements.
Final Demo Versions
These demos were all meant to be the last release before the final version, which was to be called 1.1. As such, they included only the first two Single Player zones as well as a demo-only version of Castle Eggman Zone. While the core game stayed the same in this era, several major and minor updates were made over the course of several years, all of which were labeled as the final one. This led to a very complicated and inconsistent version numbering system, as the version numbers were never supposed to reach beyond 1.09.
These releases were made after the "Final Demo" concept was scrapped. From this point on, there is no set final version and a new major release is made whenever there is enough content finished. Because of this new approach, releases from this era are substantially more complete and elaborate than before. A new version numbering system was also implemented: Releases are numbered as 2.X.x, where X marks a major version number and x a minor version number.
This was a semi-private beta version that showcased the new Match system of the 2.0 era, much like 2k3 did for the Final Demo era. It was released exclusively to the #SRB2Fun IRC channel.