Better progress today

With some hints from Phil, I've implemented better player movement controls. They're much smoother and less flakey.

I've also tweaked the visuals a bit, changing the background brickwork to look a bit more like brick, and darkening it a little. The two vertical girders are there to stop the player, and will most likely be replaced.

I've added a download for my progress so far if people are curious.

Next up, the first part of the actual gameplay: destroying the boilers! Mwahahahahaha!