I like the artwork.
Just being able to run forwards or backwards felt a bit too restrictive. It took me a while to figure out what was going on, maybe a little backstory and tutorial will help clear things up. The time the user holds space is a bit too long, I held space a couple of times wondering what was supposed to happen (the menu only says space to collect not hold space). Some background music, ambience and sound effects will add greatly to the experience too.
Overall, good entry!