0.2.8: clean up code, add temporary epilogue

I'm not sure whether the game will actually have an epilogue, but I haven't
finished all of the levels yet, so it makes sense for the game to keep going
after the credits...

0.2.7

bugfix, and audio changes

0.2.6

change star color back to white

0.2.5

Update README.md

0.2.4

replace music track

0.2.3

pixelate effect, format code

0.2.2

update stuff

0.2.1

more work on gatekeeper boss

0.2.0

bugfixes, fix healthbar issue, screen flash animation for first boss

0.1.9

misc updates