Portal is a mode of google snake game in which two "good" apples are on the board for each single apple that should spawn. When the snake eats one of them, it's head will start coming out of the other apple. A player has the ability to change direction while eating an apple by pressing a key at the right time. This allows the snake to come out of the apple in any direction, including a 180 degree turn. If the player does not change direction while eating an apple, the snake will come out of the other apple continuing in the same direction.
After the snake eats an apple, two new apples appear on the board - unless Dice count is being played. In portal mode, the apple spawn radius is taxicab three from the snake's head. The game ends when there is no more room for apples to spawn or the player dies. Because of the spawn radius, the maximum score a player can achieve without dying varies on the location of empty squares. The maximum possible score for small board is 84-85, standard board is 249-250, and large is 498-499, depending on the multi setting.
Trivia[]
The name "portal mode" was coined by 'speedrunner' "SpaceDoge" on June 11th, 2020.
The spawn radius was changed from taxicab two + three in a straight line to taxicab three in January, 2022.
In the past, before speeds were made into their own setting, the speed of the snake in Portal mode was slower than the default speed, but faster than "slow".
Portal mode is called "PORTALS" in the google snake source code.