"Portal" has also been cited as a strong example of instructional scaffolding that can be adapted for more academic learning situations, as the player, through careful design of levels by Valve, is first hand-held in solving simple puzzles with many hints at the correct solution, but this support is slowly removed as the player progresses in the game, and completely removed when the player reaches the second half of the game.Rock, Paper, Shotgun's Hamish Todd considered "Portal" as an exemplary means of game design by demonstrating a series of chambers after the player has obtained the portal gun that gently introduce the concept of flinging without any explicit instructions.