Cascade

Cascade is a Sandbox game which has interactive simulated fluids and landscapes you can modify while on a mission or in the level editor. Use aircraft, boats, wheeled vehicles, horses, snowmobiles, Choose a creative mode or an mission driven path with challenges that include drones, turrets, monsters, bases to attack. 

There are single player missions that involve first person characters, horse back, aircraft, driving, boats and more. these involve  challenges of exploration, quests, attack, divert rivers etc, fun ! 

The level editor allows you to :

Modify landscapes and the fluids will update in real-time.
Add simulated fluid sources that will follow the landscape. (Water and  Lava,)
Add large volumes of liquids.
Change the landscape auto material.
Paint trees and grass.
Place objects that interact with the fluids - rocks, buildings, bridges, floatable objects.
Add lights, particle effects, volumetric fog.
Change the time of day and weather.
Place enemies like drones, turrets, monsters etc.
Explore your creation on foot, on horseback, on a Dragon, in an aircraft, wheeled vehicles, boats, submarines, snowmobile.
Add premade railways. 
Create rivers, seas, lakes, and Volcanos. 
Add drains to control the levels.
Create dams then burst them or divert the fluid anywhere.
Import terrain heightmaps.
Import 3d models, .GLB, .fbx,  move, scale and rotate them. basic animation support.
Save your creations .
Record fly through video to 2d, 3d, vr180, 360 formats up to 8k .