Controls:
1     - Wall
2     - Sand
3     - Water
4     - Fire
5     - Wood
6     - Coal
7     - Oil
8     - Hydrogen gas
9     - Hydrogen liquid
0     - Air
LMB   - Spawn particles
Space - Toggle pause
Minus - Decrease simulation speed
Plus  - Increase simulation speed
>     - Simulate a single frame (speed dependent)
F     - Toggle fullscreen
Tab   - Toggle super secret menu (don't tell anybody)