I bought this game during the 2014 holiday sale when I had a few bucks left over and nothing else on my wish list. I am very glad I got it now, as opposed to the other prospects I had lined up.
This game plays like Risk, but has some really awesome new mechanics that make the game worth getting. The biggest mechanic is the game's titular use of greed to change the landscape: you can use harvesters to work the land and get money, but ever time you do, the land they stand on is slowly lowered until it collapses. This introduces some seriously awesome strategies in the game; one time I planted a harvester in the middle of an enemy island in order to collapse it and take out everyone on the island. I didn't have to use any of my troops or engage in a time-consuming siege- all I had to do was attack an unprotected square my opponent had left neglected, plant a harvester there, and laugh as the ground literally crumbled under their troops.
This review is getting really long, but let me just tell you this before I finish: GET THIS GAME. It's definitely worth it, and the only things wrong with it aren't even part of the game itself, they're problems with the developer, whom has discontinued supporting the game and thusly Greed Corp's servers are dead.
The campaign is about 10 hours of gameplay, and it's pretty nice. However, the true worth of this game comes from the multiplayer, which can still happen... we always find a way. My only regrets is that this game doesn't have any steam workshop support, and that the developer seems to have done a disappearing act.