UI suggestion: from what I saw in the demonstration video, all of the in-game text is too small (especially the popup menu when upgrading towers), and the planet names' font + color make them too hard to read well. Picking good fonts, colors, and sizes for players be able to read everything instantly is critical for a sound game. IMO the turret names (Phoenix, Shark, etc.) should take up the entire width of their sidebar. There is certainly enough margin for them.