Music and moving walls

In this final (?) update I added music to the title and high scores. The initial number of monsters and treasures now correspond to the level, such that at level 1 there is one monster and one treasure, at level 2 there are two monsters and two treasures etc. To make the game a little bit more challenging I added moving walls. This means you could trap monsters, but also yourself by accident. 

Even ithough this is the final post (probably) there are many possible extensions, such as a final goal and a story. The game was supposed to be about a viking in space, but this is presently not very clear, and could be futher elaborated upon.