Right now the only way to gain access is to purchase a founders pack or be invited as a Tester. These packs do not give any pay2win benefits and are mainly cosmetic items, and most of the items in the packs are not in the game yet and will be available as the game is updated etc.
The income generated from the founders packs is being used to develop the game as it is an Indie company making it and they have no financial backing (which is honestly a good thing, no big game company telling them how to do things and when to release even if its not ready just to make profits).
The game currently is in its early Alpha test stage, so you are helping fund the development of the game and bewcoming an Alpha tester to play and report bugs and help make the game great.
Honestly the game in its current state is way more developed and polished than so many crap games out there that are in actual release. Yes it has bugs and some issues but thats why its in alpha
Once the game releases it is my understanding (and I may be wrong a bit) that the game will be free2play, with a premium shop with cosmetic type items only that do not affect gameplay other than maybe XP/credit boosts and so forth.
Oh, ok, so it is f2p. It's just that I've been under impression that the title was going to be buy2play, and than I saw premium currency among reward tiers and got freaked out since b2p+premium currency never bode well.