Let me start off by saying first that Star Sky has a nice concept, but the content is not here. The attempt is there, it's a unique concept, but a far too expensive one with far too little content available.
My first impression from reading the description of the game was that there would be multiple roads to walk down, and it's ultimately left up to the player which roads to take. This is not the case. What you do is hold the right arrow key, continuously walk right, and stop whenever you hear music playing so that you can trigger events.
There are multiple ways to trigger events, and there are a total of 18 events to trigger; each one with their own achievement. However, in a mere 22 minutes I unlocked 14 of the 18 events. This game isn't very long at all, in 50 minutes I unlocked all of the events, and at an asking price of nearly $5.00 CAD it's just not worth it.
I could defend the value of the game if the graphics were more than 'stylish' silhouettes with backgrounds that would've taken a couple hours tops to make in Photoshop. The fact that Star Sky has the same look and feel to it that any browser based Flash game does really doesn't help to push this game at its selling price, either.