Am I reading it correctly that you kickstart and they offer you the beta at a pre-release price for that? Meaning you give them X dollars and then they allow you to buy the beta?
Game looks like it could be fun, it could also end up being massively irritating/boring. Pacing and unseen features/details will make the difference. If it just amounts to keeping the guys from digging themselves through the island and building castles, that'd be pretty boring.