To clear things up:
Alpha is a release that can have missing features, levels, and bugs. Usually sent to publishers to find business opportunities.
Beta is a release that has all features, all levels, but may have placeholders and bugs.
Some prefer to call very much tested betas by the name of "gamma"
After testing the beta for some time and having replaced placeholders with real art, fixed most of the bugs, you can release the 1.0.
Final version is the last update to the game.
Alpha is a release that can have missing features, levels, and bugs. Usually sent to publishers to find business opportunities.
Beta is a release that has all features, all levels, but may have placeholders and bugs.
Some prefer to call very much tested betas by the name of "gamma"
After testing the beta for some time and having replaced placeholders with real art, fixed most of the bugs, you can release the 1.0.
Final version is the last update to the game.