Post-Jam build!

It's been a couple of months since the jam, but I've been excited to improve on this game after seeing people play the original version!

Here are some of the big improvements:

• There's a brand new level now! If you played the original, the new one is now inserted into the list as Level 4. 
• Lightened up the visuals so that it's easier to see puzzle elements in the dark. Improved the visuals and lightening in a lot of other subtle ways, as well!
• The controls should feel a lot smoother now, and it supports the arrow keys in addition to WASD.
• Doors make a sound when they open and close now! They were oddly silent before.
• Lots of little tweaks to various levels to smooth out the learning curve.
• Added an Easter Egg for players who solve a puzzle in an unintended way.