RacingCart3D: tilt the phone, watch the kart on the television
RacingCart3D puts a small kart on a closed track and asks you to drive it by leaning a phone. The television is the world. The phone is the wheel, the accelerator, and the brake. One person can race alone. Four is the full grid. There are no computer drivers, so a solo session is a time trial, not a race against a ghost. If you wanted opponents, they have to be in the room with a phone each.
1–4 players
How to play
1Three laps, first across the line
One to four karts race three laps.
First to finish the third lap wins. Everyone else is ranked by finish order.
One player is a time trial. There is no computer driver.
- LR
2Tilt the phone to steer
Lean the phone left or right. Holding the lean holds the turn.
Flat, or after you recenter, the kart goes straight.
A phone without motion sensing can still use the pedals.
3Hold the gas, tap the brake
Accelerate and brake are buttons on the phone.
Let go of the gas and the kart coasts down.
The television shows the pack. On a computer, Player with own screen uses arrow keys or WASD, and Space brakes.
4Coins are a bonus
Coins sit along the lap. Each kart collects its own, once per lap, then they return.
The count shows on the results.
Coins do not change who finished first.
5Pick a track and a color
The lobby has five tracks: Oval, Kidney, Chicane, Hairpin, and Island.
Each kart claims a color. You can ask to swap.
The choice is locked when the lights go out.
6Wrong way, then a rematch
Driving against the arrows shows Wrong way on your phone and on the TV.
After the finish, everyone has 20 seconds to vote for another race.
A yes majority starts the same track again. Otherwise you return to the lobby.
Before the lights
Host on the TV or, better, a laptop on HDMI if the TV browser is weak. This view is a 3D world, and a tired television will show it. Friends join from phones, up to four. In the lobby each racer claims a color. Eight neon colors exist, and two people cannot wear the same one. If you want a color someone else took, you send a swap request and they accept or decline. Colors lock when the race is about to start.
The host picks the track: Oval, Kidney, Chicane, Hairpin, or Island. If nobody picks, the room code chooses one. Then there is a ready period of about ten seconds — turn the phone sideways, allow motion access if the browser asks, and tap to enable steering — followed by a 3–2–1. The race is three laps. Finish order is the result. A wrong-way banner appears on your phone and on the TV pane if you are heading backward. It does not turn the kart around for you.
What the phone is doing
Hold the phone in landscape. Lean left and right to steer. The lean is relative to a center you can reset with Recenter, which matters after someone shifts on the sofa and the “straight” position is now a curve. Accelerate and brake are buttons. If the phone has no gyroscope, or permission was denied, you still have those buttons, and the game will say so. Steering without tilt is clumsy. A phone that can tilt is the controller this was built for.
The kart has wheels and a driver, and the track edge is a low curb rather than a wall. Run wide and you scrub speed. The physics cap is the same family of numbers as the hover race: this is an arcade lap, not a simulation of tire temperatures. Sound can be muted from the phone. After the finish, everyone votes on a rematch for twenty seconds. A strict majority of yes starts the next heat on the same track. A tie, a timeout, or too many no votes returns the room to the lobby. One racer needs one yes. Four racers need three.
Solo, and with a crowd
One player is legal. You still get the countdown, the three laps, and a finish. You do not get a rival kart. Use it to learn Hairpin before friends arrive, or to see whether this television can hold the frame rate. Two players is a duel and the easiest way to teach the lean. Three and four fill the screen and make the first corner a negotiation.
There is no way to drive this from a single device that also shows a private board. The world lives on the Main screen. If someone is remote, they would need to watch your TV through a video call, which is a poor substitute. This is a couch game.
Driving notes that are specific to this kart
HoverCart3D uses the same laps, tracks, colors, and phone controls, with a floating cart and tall side walls. Race this one when you want wheels and a curb. Race that one when you want the cart to bob and the road to keep you in a trench.
- Recenter before the 3–2–1, not during lap one. A bad center feels like the game is steering for you.
- Brake before Hairpin. The curb slows you, and the kart does not have a wall to lean on.
- Pick a color you can see against the grass. The neon set is there because a dark TV eats dull paint.
- Oval is the teaching track. Island and Hairpin are where a learned line matters.
- Vote quickly at the flag. Twenty seconds and a missing vote count as not-yes, and the room drops to the lobby.
FAQ
Are there computer opponents?
- No. Every kart is a person in the room. One player means a three-lap time trial. Invite friends if you want a race.
How do I steer?
- Turn the phone sideways, allow motion if asked, and lean left or right. Accelerate and brake are buttons. Recenter sets a new “straight.” Without a gyroscope you can still use the buttons, but tilt is the intended wheel.
How long is a race?
- Three laps. The start is about ten seconds of “get ready,” then a three-second countdown. Afterward a rematch vote lasts twenty seconds and needs a strict majority of yes.
Which tracks are there?
- Oval, Kidney, Chicane, Hairpin, and Island. The host picks in the lobby. If nobody does, the room code selects one.
Can I play without a TV?
- The race is drawn on the Main screen. Phones are controllers, not a full private view of the track. Use a television or a laptop everyone can see.