Alpha
Also said as Feature complete, Feature freeze
The point when every feature is in the game and can be played, however buggy and however ugly. After it, the rule is that no new features go in. Each studio draws this line slightly differently.
Every new feature brings new bugs. Bugs can only fall to zero once features stop arriving, so a game with no alpha date has no real ship date either.
Say it
“Alpha is 1 October. Anything that is not playable in the build by then gets cut, however good it is. After that date we only fix what is already in.”
Where you’ve seen it
Minecraft made the word public. Its alpha began in June 2010, and people could already buy the game while major systems were still being added. Inside studios, alpha usually means something much stricter.
Not to be confused with beta
At alpha all the features exist, but content and quality are still rough. At beta all the content exists too, and the only remaining work is fixing bugs.