I haven’t tested alot of alphas, but just wanted to know if it has an expire date.
What do you mean by expire date? Usually early access games are gradually updated and each version is playable as long as you have the binaries.
masozravapalma is right. As in other alphas, the game will be gradually updated, so backers can test new game features and content.
As stated by the developers:
The Tech Alpha version of Kingdom Come: Deliverance is a collection of several technical aspects and game mechanisms in a more or less advanced state of development. The playable content will grow in stages (updated versions approximately every two or three months), adding new aspects, settings or game mechanics to the Alpha. You’ll get the chance to become acquainted with Kingdom Come: Deliverance step by step and can delve into more and more of our world as the amount of the content grow.