I've noticed that the time it takes to complete the first level and understand the aspect of the game can take a long while. Given that, I decided to change it up a bit and make the first 3 levels available, as it would be a better experience to figure everything out while having different areas to do so in. The last 2 levels are still non-accessible until previous areas have been completed, but this way you have multiple areas to try out and hopefully provide a better experience that way.