My only complaint is that the in-game achievements were very boring. They could have added some optional difficulty, such as "Get all the gold in a level" or "beat level 20 with a ship made from only one type of item"
I'm also having issues playing it... maybe the server's just getting hammered right now? Sometimes the menu will flash on for like a frame and then it just goes to the background logo, or black. Extremely frustrating.