3D game ideas that need the third dimension

Make a game 3D when height, depth or physics are the point. Super Mario 64 (1996) was built around running and jumping in open space, and Only Up! (2023) is a game made almost entirely of height. Below are 3D ideas in three groups, a few easy ones for beginners, and a sentence for each to try in Roam.

When 3D is worth it

3D costs more to make and is harder to control on a phone. It pays off when looking down is scary, when objects fall and break, or when the camera shows something a flat screen cannot. If your idea plays the same from the side, a 2D game may be better.

3D ideas for height, physics and flying

Height: Junk tower. Climb a tower of furniture and fridges. Try: "climb a giant junk tower into the clouds, one fall sends me down a floor"
Height: Window cleaner. Clean windows on a skyscraper in the wind. Try: "window cleaner on a skyscraper, wind pushes the platform, clean 20 windows"
Height: Bird's climb. A small bird hops up a sky island to find seeds. Try: "small bird platformer on sky islands, find 14 seeds, wind gusts"
Physics: Demolition. Pick a tool and bring a building down. Try: "voxel demolition, pick a tool, bring the tower down in 3 hits"
Physics: Stunt drop. Cars race down a long orange track with loops. Try: "stunt race down a giant orange track with loops, 8 cars"
Physics: Stack it. Stack crates on a moving truck. Try: "stack crates on a moving truck, every turn they slide"
Flying: Paper plane. Glide through a house without touching walls. Try: "fly a paper plane through my house, rooms get narrower"
Flying: Deep dive. Swim deeper for treasure as light fades. Try: "deep sea dive, find treasure as it gets darker, air runs out"
Depth: Arena duel. A 1v1 shooter where cover and height decide. Try: "1v1 arena shooter, 5 rounds, high ground wins"

3D ideas for beginners

Start with one room and one camera that follows the player. A ball rolling through a maze, a 3D obby with five jumps, or a target range are small enough to finish. On Roam you describe it and it comes back as a playable 3D game, so you can test a camera idea without an engine. Roam games to look at: DEMO DAY, a voxel demolition puzzle. HotWheels Loop Drop, eight cars on one orange track. CLUTCH, a 1v1 arena duel over five rounds. Peck the Sky, a 3D sky platformer.