1. Realtime water reflections, without adding a water shader (leaving the original water texture)

2. Sun shafts when the sun is shining into a cave or darker area.

3. Focal blur

4. Lens dirt (mod can alter texture)

5. Lens flares

6. Light glow, from glowing items like torches and lava.

7. Realtime shadows, which truly enhance the complete experience of the game - in my opinion.

8. Color tinting for terrain and biomes, similar to Minecraft. Makes the world feel more natural.

9. Underwater effects like displacement, sun shafts and water texture being overlaid on blocks.

10. Not really a visual effect, but rain/snow/thick fog.
