In this video you can see the current features I’ve worked on so far, in brief summary;

Day/Night cycle, timeline in the level BP that drives the sun to orbit the scene
Bats, Particle system that has a chance to emit bats at night
Fog, Fog with DoF blur that washes in with it and blurrs stuff out
Spooky Rocks, Just rocks in daylight, during night have a chance of spawning eyes.
Fireflies, particle system that has a chance of emitting fireflies at night (with lights on them)
Ocean, with various adjustable variables like wave height and wind direction.
Sparrows, Particle system, 3 possible variants. Uses spritesheet and SubUV to animate particles
Butterflies, Particle system, Uses spritesheet and SubUV to animate particles

Have also done some testing on a Northern lights system, but not very happy with that yet, so that’s gonna need some more work!

Some of you may have come from Twitch, where I’ve been streaming my progress: 
 I’ve had some brilliant interactions on the stream lately, also had some great tips through to make the whole thing run more smoothly! Feel free to drop by when I’m live and ask me questions!