Rapid Fire Update and New Demo

We've got another update for you, just small one in terms of changes but big in terms of impact. - Fire rate increased to make missions easier (and more fun!) - Explosion screenshake added (because it's cool) - Fixed game not pausing when using Steam overaly (because that sucked) - Changed health and grenade icons to make it easier to keep track of things - Updated environment and enemy selection to avoid see the same ones too often We've also updated the demo version to include all the recent changes, so that it gives a more accurate impression of the full game.