Added light source + fuel mechanic.
Added frame rate and v-sync options.
Added color options for keys.
Added credits page.
Changes to weapon model, animations, and sound effects.
Changes to enemy difficulty scaling.
Changes to distraction mechanic.
Changes to note text content.
Changes to various visual effects, lighting, fog, and tone mapping.
Changes to various object models.
Changes to various sound effects.
Minor bug fixes.
