One's 5 dollars less than the other. I've seen Kickstarters do this, where there's a special low price tier for getting certain rewards, but there's a limited number. In theory, early adopters all buy in at the $30 mark, then people who come later are stuck with the $35 one, like a pre-order discount, with lots more pre-. In practice, fans get confused and pay for the more expensive one with the assumption it's better than the cheaper entry.
In general though, I've got all sorts of bad vibes from this project. When I first heard about the game it sounded like he had full funding already, but his investors wanted to play a fake Kickstarter game to "gauge interest".
I'm surprised there's a wildly ambitious space game being promised without anyone referencing Battlecruiser 3000.
Yeah, but what's happening here is that there is a $30 limited tier, a $35 limited tier, and a $40 unlimited tier. Kinda lol imo!