Mini Pinball hot fix 0.6

Patch based on your feedback:

1. Reduced wall height for better visibility.
2. Adjusted wall colors to be less bright.
3. Added graphics settings and enhancements (example in the screenshots). Now you can enable or disable post-processing in the settings (which was not available before).
4. Added 2 new levels. Now there are a total of 12 levels.

Fixes:

1. Fixed ball getting stuck on level 1.
2. Fixed disappearing targets on level 4.
3. Moved the sound settings UI closer to the closing button.
4. Fixed the bug where level 4 was completed, but levels up to 9 were already unlocked.