more content
It takes me less than an hour to beat zone 5, the current "endgame", with a fresh character. The beta's supposed to be short right now, but we'll need much more than an hour before recruiting many more testers.
Add a few more zones, a few more production units, some achievements. (Achievements are especially sparse right now - nothing for combat, nothing past drones, basically a crude tech demo.)
Stay away from a generated-content-endgame for now (like neverending zones, greater rifts). Keeping the game deliberately short gives beta players a reason to come back and play again as we add more content, and we don't have to worry about the jump from fixed-content to generated-endgame-content yet.
Edited by Evan