Improve game-ending conditions on meteorite rain game #1

Relevant Asana thread: https://app.asana.com/1/24168105893189/project/1205799882624212/task/1213617000680022?focus=true

Basically, meteorite rain game terminates only when all lives are lost. This makes the UX of the game somewhat unintuitive. A better approach would be to also have another type of counter (time-based or characters/words typed counter) and use that as well for the termination condition.