Got the game up to a state where I felt I could get people to test it, and that's what I did last Saturday. My school was having a PC Game Night and used the opportunity to get a bunch of my friends to play the game and give me their impressions.
A counting bug crippled the tutorial level, so I had to resort to teaching the controls to players, myself. In the game, I have players piloting a spacecraft in zero gravity and all the controls are for the ship's thrusters. This includes six keys for translation thrusters (forward/back, side to side, and vertical climbing), and another six keys for rotation (pitch, yaw, and roll). Writing it down, it sounds like a handful, but I thought the controls would be easy to use once learned.
As it turned out, all my players had some difficulty handling the controls. I even taped a couple of index cards to the monitor with the controls drawn-out in marker, and it didn't help.
There were some other issues that came up during testing, but the controls were the one that got everyone. I have about a month and a half left to update the IndieCade build, so I'm starting to have to really prioritize what gets done. Controls are now definitely first on the list.
The one thing I was very glad for was most people seemed to have a very favorable opinion of the game's feel and general atmosphere. Nobody appeared to get motion sick, and they quickly grasped how to work the thruster mechanics (minus which buttons to press). So overall, the test went very well.
Now to figure out what to do with the controls...