For some time now, I've been thinking about how games calculate physics. Take as an example the game TrackMania. There are special routes where you only have to accelerate from the beginning to get to the finish. As an example, I take the following YouTube video (https://www.youtube.com/watch?v=uK7Y7zyP_SY). Unfortunately, I'm not a specialist in game development, but I know roughly how an engine works. Most engines use a game loop, which means they use the delta value between the last call and the current call. This delta value is used to move objects, detect collisions and so on. The higher the delta value, the farther the object must have moved. The principle works fine with many games, but not with TrackMania. A PC that can only display 25 FPS would calculate the physics differently than a PC with 120 FPS, because the collision detection is more accurate (impact is detected earlier, speed adjusted accordingly, ...). Now you can assume that the delta value is always the same (as with Super Mario Maker, at least that's my assumption), then this would work. But that would cause problems similar to old games (https://superuser.com/questions/630769/why-do-some-old-games-run-much-to-quickly-on-modern-hardware/).
Now my question, why do such maps work on every PC and why is the physics always exactly the same? Did I miss any aspect of game development / engine development?
The answer is simple, first the physic of the game is predictable, based on the input the result will always be the same.
Then the physic loop is not the same as the render, the game ensure the physic loop will be call with exactly the same period every time during the whole execution. So, yes a delta is needed for the render part, but the physic as a constant time in ms between each iteration.
One last think : you wont find "Press Forward" maps on the multiplayer, these kind of maps will not work correctly, this is directly linked to specificities in the physic to avoid TAS (Tool Assisted Speedrun).