A games longevity usually comes down to 2 things, multiplayer and Customization.
Since this will probably be single player & turn-based, multiplayer doesn't enter into the equation.
But customization does, look at recent games like Minecraft which sold cheaper Alpha versions prior to it's release. Because of the modding that game will have a long life. And other games like Doom, people are still making WADs. And Thief, people are still making Fan Mission with an outdated graphics engine and editor.
If the developers were to show that the game isn't just a "play a couple of times with different party members or tactics, and then never play it again" kind of game, there would be a broader interest in the Kickstarter.
And that would be to have a Level Editor so that users could make custom scenarios, which would include Maps, Items, Weapons, Skills, NPCs, Dialog trees and Flags. Also a custom scenario loader would be need to make it easier for end users to load other people's levels.