Add Air timer. Adjust scoring. Fixes #5
Add Air timer. Adjust scoring. Fixes #5

The air timer is generous at 50 seconds. The game gets hard
enough at later levels. The time is for just gentle pressure
and for more interesting scoring. The score curve was also
adjusted. Level bonuses count for less now. Before this
clearing level 2 was worth double level 2, and level 4 was
4x level 1. Now level 2 is 1.2x level 1, and level 6 is 2x
level 1.

This way individual level performance (now that it exists)
isn't completely eclipsed by getting to the next higher level.

walsh9/secret-treasure-of-the-octopuses,walsh9/secret-treasure-of-the-octopuses