I think that you couldn't unlock the other levels because you didn't finished the levels xD Mainly the goal of the game is yes to bring the packages to the spot, but after that you must return to the base to actually complete the level..
About the tutorial, i know it wasn't really clear, but with the short time left i couldn't actually do more, for that i'm sorry.
I hope you can try it again and submit a score in the leaderboard after :)