actually... a good idea????
ive been scrolling through the comments for a while and most people are either "GIEV KEY" or "just buy it on steam"
multiplayer dedicated servers would be a good idea
another good idea would be just bake the achievements into the game
another good idea would just be have the leaderboard data be from local attempts (like arcade style)
this is the first one I've seen to have a idea (other than "just send key to all of us")