Installation Issues

I just purchased Dark Avatar last night. I'm very frustrated as there are no instructions on how or where to download the game. If I'm gonna be paying $35 for a game I expect to be able to access it in a painless way. So far, I've had to install this Stardock Central. I thought I might be able to download the game from there, but it's not very intuitive. I prefer buying games in the store. They're supposed to be fun. I like to spend what little free time I have playing games, not surfing the internet trying to figure out what I have to do for a game expansion I just paid $35 for (a premium price). Can anyone help?