The Alpha is not available on Steam. It exists as a ghost. You can find it buried in archive.org or old GameJolt links. Patches (v1.0 to v1.3) changed minor elements, but the original Alpha is a lost-media treasure hunt.
When players boot up the alpha version today, they are often struck by how primitive it looks compared to modern standards. However, this primitiveness is exactly what gives the its unique charm and, arguably, its horror factor. slendytubbies 1 alpha
The represents the rawest form of this vision. It was a time when the game was not yet a polished product with a narrative campaign or multiplayer lobbies, but a pure, distilled proof of concept. It was an experiment in cognitive dissonance—taking something safe and corrupting it. The Alpha is not available on Steam