This is the earliest build known to be existant in the wild of In The Groove.
Some elements from this build noting as a comparison from the Roxor website back from the day (Dating December 2003):
Duo battle is present but not actually fully working. Attacks can be achieved and sent to a mysterious third opponent that is running on the background as the attacks are not sent to the accompanying player.
Most songs shown on the first screenshot are not present, they would start to appear on the July alpha and onwards.
Seems to be the first build to have the 3D wheel implemented...?
VerTex is credited to Kyle Ward in this version, not ZigZag.
The audio is slightly different as well specially at the second break.
The charts for this song also end abruptly before the song can end.
Tempest mode (As seen in one of the screenshots), an unique perspective mod is present, and it's only current known build to have it.
This build features a GrooveBar, which is the triangle representation of the stats seen on the Music Wheel. It had some iterations before being taken out (even being present on OpenITG) during the SM4 transition.
It comes with three noteskins, which have lighting embeded into them to reflect from the metal border, depending on their current position and player's current perspective.
Up until the beta, the game only carries three difficulties: Chill, Jam and Killer, which contrasts with the available difficulties that SM3.0 already had.
It contains several versions of the theme, with varying grades of progress and stability.
The difficulty selection screen (on groove.not-cvs) theme has no limit of what difficulty to pick, so you can go out of bounds on the selection.
Similar to StepMania 3.0, pressing start at any point on any ScreenOptions generated screen will instantly end the screen and save settings.
This version of the theme has support up to 7 stages (including final).