Portal 1 literally has a line on the floor you are supposed to follow, and only a handful of items in each room you can interact with.
Then there is also that you are only allowed to place a single color in the beginning. Limiting your options.
Almost like a good game explains the mechanics and actually helps the player grasp the concept of the game over a period of time, before throwing them into the deep end.
Portal 1 literally has a line on the floor you are supposed to follow, and only a handful of items in each room you can interact with.
Then there is also that you are only allowed to place a single color in the beginning. Limiting your options.
Almost like a good game explains the mechanics and actually helps the player grasp the concept of the game over a period of time, before throwing them into the deep end.