Yeah, good stuff
At first I was quite sceptical when I saw "Half the fun is working out what on earth you're supposed to be doing" But as soon as I did (and it didn't take too long :) ) I started really enjoying it. It's very well made, very smooth, with no visible glitches and some good music. The only things I can think of doing to improve it is make more types of objective, and make difficulty levels, by giving lives, eg 3 lives per objective for easy, 2 for medium and 1 for hard etc...
Overall fantastic work, that's the kind of stuff I want to see making it into the portal on a regular basis. Can't wait till your next submission.