future enhancements:
- score
- leaderboard
- play against recordings of past/top times
- maps
- TMX support with Tiled Editor
- enable people to create + upload their own maps, server generates + stores hash short url
- timing
support waiting/timer to start at the same time- timer to time how long game is taking
- powerups
- people can go in out-of-the-way places to get powerups