You don't manually spend the research points, they just get accumulated automatically until it's enough to fullfill your current research.
For building the spaceship, you might need to spend wood and gold, and you need a village.
Yes got my spaceship, the ending is a nice touch ;) Got the tutorial alert "you have to spend your research points" at every turn despite having apparently done all researchs, i guess it's a bug
Oh right, I missed that. Thanks for pointing that out!
