Updated to v0.2

The game has been significantly updated and polished for a release at Redditaisai 2018.

Changes from v0.1 to v0.2:
- New title menu. Added pause menu and results screen.
- Changed game resolution from 1024x768 to 1280x720.
- Added fullscreen mode options (fit, crop, stretch).
- New background music.
- Added volume sliders.
- Four difficulty modes.
- Many gameplay tweaks, including the addition of barrier blocks.
- Character dialog.
- Respawn button.
- Lots of minor tweaks.

I warmly welcome any feedback on the game in this state. There are still many changes I wish to make, such as improving the graphics.