Humans are not always predictable sadly, so this tutorial may not work.
Getting a World Idea
All games/worlds start with an idea, so you need to get one. A good place to look is the front page of the actual Roblox site.
There are a few trends on the Roblox front page, one of which is simulators. They are very popular on Blockate due to them being easy to figure out and make. The term "simulator" is very broad, however, so there is a lot of freedom on what your world can be about.
Obbies are games where the player must pass obstacles to progress. If it is difficult, people may buy items to play better, which can be used to your advantage. If you put in enough effort to make it long, you can get people to stay a while. If people stay longer, it is more likely they will accumulate and get enough players to land on the front page.
Foundations of your World
Of course, you need a place to make this world, so create a new world, or use an old one if it is available.
Most simulators have stats like money which the player can use to buy in-game upgrades and items. Simulators in Blockate are often incremental due to the limited tools. Still, there are a few distinct types of simulator.
These games start with the player being at a very slow walkspeed. The player collects coins around the map, which can be used to gain power ups to make them go faster, and reach more coins. This continues until they reach the end.
Examples: Candy Simulator, Speed Simulator
Collection simulators consist of a map with many areas that contain specific items the player must locate. When they place gets most or all of the items, they can progress into the next area. Sometimes the player is given an item that they use to progress.
Examples: example1, example2
Obbies require a stat that would show which stage the player is on. There are stat teleporters that bring the player back to the stage where they died. Obbies usually start with a few simple obstacles like lava jumps or lava checkers, but to keep players in you need to make unique obstacles, so this kind of game can be difficult to make.
Building a Speed Simulator
To start making the world, add a points or money stat. Add stat teleports at spawn that go to power up blocks. You will need to decorate the stat tele so it appears to contain the actual item. Place obstacles that require higher and higher jump power / walk speed to get past. Place enough money or points on each obstacle so the player can upgrade once they find all the points in the area. You should hide some of the points.