Read on to find out what the ground of the scene can be like in different types of games. If you start making a game from scratch using an empty scene, the ground is by default flat and endless. You'll run into different ground types when you make remixes from templates or other people's games so it's useful to get familiar with all of them.
Navigate to the Build tab and tap Ground.
Ground type dropdown menu lets you choose the between the types Empty, Infinite Plane and Heightmap - scroll down to see what kind of games each of them works best for.
World Bottom Bound slider sets the lowest point of the game world. Together with the Destroy Out of Bounds toggle you can define that objects that fall past this bound will be destroyed automatically.
You can also adjust the physical and visual material of the ground. See below for details!
The default ground type - flat and endless Infinite Plane - is great for eg. games where the player sticks to ground level or eventually hits the ground when falling.
You could also use the Infinite Plane setting for scenes where you need a body of water: with the physics settings of objects, and logic, you can make things float halfway in the sea, or you can have the player start to swim (or die) when it hits the water.
When the ground type is Infinite Plane, the World Bottom Bound is on the same height with the visible ground level.
Even if Infinite Plane can look a bit dull in the beginning, don't let this fool you: you can create interesting landscapes with the help of tilesets and models!
Sometimes you don't need a ground at all - maybe your game takes place in space, or you're making a puzzle game. Platformer games in which a player can die by falling very often make use of the Empty ground type.
Dynamic objects will fall endlessly, unless you place something that stops them to the scene. Remember you can destroy falling objects with the help of World Bottom Bound.
Another option for games in which you need a ground is heightmap: it creates a rolling landscape. The heightmap feature in HypeHype is still being developed and it has some drawbacks compared to infinite plane: heightmaps are not endless, and the heightmap editor used for defining the steepness of the hills doesn't show the changes in the editor until you quit and come back.
So you've chosen the ground type, or maybe you've replaced the ground with platforms. What if you wanted to make the ground or platform icy and slippery, or control how hard objects bounce back after falling? You can adjust the physical material of the ground, and change the visual material as well.
It's possible to assign the same materials to the ground and any other objects (rocks, tilesets) you've used to create a landscape, in case you want them to behave and look similar as the ground.
Here's a small example video on how to create an icy surface by editing the physical and visual materials:
Ground Materials