Sounds, base hit points, waves - we're feature complete!

We are feature complete! We think. There's only one (new) level in this build, but the final version will have a couple more (and possibly a level selection menu).

However:

• Base hit points can be tracked next to the resources; if you run out of them, the level will end and you can restart it by pressing R. One base hit point will be subtractied when an enemy reaches a base.
• We have pre-defined phases during levels: prep times and waves. You track the current phase and how many seconds remain before the next one starts in the top right corner.
  • During prep times you have some time to move stuff around and build defenses, without enemies spawning all over the place.
  • During waves enemies will spawn in a pre-defined but slightly randomized manner. A wave will last a fixed number of seconds, but spawn intervals are randomized between a minimum and maximum value. The possible enemy times for a wave are defined as well but if there are more than one, it will be randomly choosen at spawn time.
  Oh, audio! We have sounds. You can mute them by pressing M if you don't like them. We might get rid of the player "drone" (no pun intended) and add music instead.

We still have levels to design, optimize performance (we have major problems in that department), playtest everything and try to balance stuff... please feel free to report bugs or annoyances!