Hi! Right now there is no platform that offers "buy once and get all future years of updates for free", unfortunately. To keep being able to work in the pace we are working, the subscription model is the only way. We will publish the game on steam at some point. We are not a big studio with budget - everything we bought goes out of our pocket and all the hours spent working on it are hours that we dont earn money from some big company contract. That's why it is like this for now ;)