I know alot about ue4 
So i can tell you exactly what you should do. 
**
Rendering**
- Make button to deactivate Motionblur
- Make button to deactivate godrays
- Make button to deactivate lensflare
- Make buttons for SSAO enable and its quality settings
**
Gameplay** - Make movement harder so that the items and the arms dont move up and down so slow
- Remove shadows of items in hand and handmesh shadow itself
- Hotbar scrolling should be in the other direction
- Height of player is wrong, should be 2 blocks height
- mouse sensitivity settings
- autosave on map leave
- interaction animations with same speed as the actual action
- menu for speed settings
- flying option? maybe. classified
Sounds
- Make music volume sliders
- more feedback sounds on interactions