Within a Deep Forest

Within a Deep Forest is a freeware 2D platform game created by Nicklas Nygren, in which the player controls a bouncing ball. The ball can be transformed into different materials, such as rubber, iron, or glass, each with different physical properties and abilities (such as glass being immune to lasers.) The order in which the materials are acquired enable the player to enter different areas or make certain locations easier to navigate, giving the game some elements of the "Metroidvania" genre.

There are save points (called warp spots) placed throughout the game. The player can only change the ball material at a warp spot. Many hazards, including spikes, water, lava, and certain creatures can kill the ball, and upon death the player respawns at the last warp spot visited. There are no "lives" or a time limit.

The game was developed in Multimedia Fusion. Nifflas had begun work on a direct sequel that was later abandoned, but many elements from Deep Forest, including the ball and some of the locations and plot elements, were later carried over into Knytt Underground.

Plot
The game's story starts in the year 2500, after a devastating war has left the Earth a desolate wasteland. One of the survivors, the infamous and notorious Dr. Cliché, creates a time machine that enables him to travel many hundreds of years back in time in order to complete his most dastardly deed, the building of an underwater laboratory in which he has placed the most powerful bomb the world has yet known.

According to the game's introduction, "If ever this bomb should explode, the entire planet will freeze and all life will be lost. In this way, Dr. Cliché aims to eliminate beyond all reckoning the possibility of such a future ever coming to pass." As the game starts the bomb has been activated and the world lies in grave danger. The bomb is in fact Dr. Cliché's second attempt as "his first attempt failed and instead lead to the creation of a ball, although, no ordinary ball." The player controls this ball throughout the game.

Gameplay
The player can move the ball around in mid-air using the arrow keys, and may hold down the S key to bounce higher (comparable to jumping in other games), or the A key to minimize bouncing.

After completing the tutorial stage, Harara Mountains, the player may enter a hub level called Pinewood Heights, from which they may access any other level in the game. At the end of each level, either a new ball material or a useful hint regarding another level can be found.

Ball materials can be changed at save points and are used to alter the bounce height, speed, and abilities of the ball. Certain ball materials are required to access certain levels, and the player needs to collect all ten ball materials before the final level, Dr. Cliché's Underwater Laboratory, can be accessed.

List of ball materials
In addition to these abilities, the iron ball, glass ball, Yoga ball, rubber ball, and Ball of Ascent are all immune to spikes.
 * Blue ball - The standard material which the player begins the game with.
 * Pink ball - Obtained at the far right of Pinewood Heights. It can bounce slightly higher and move faster than the blue ball, but is a bit more difficult to control.
 * Iron ball - Obtained in Shinock Reign. It cannot bounce very high, but wind has almost no effect on it. It is also used to break the cracked surfaces blocking the entrance to Markstone Ridgemine and Ljus.
 * Speed ball - Obtained in That Hover Thing. It can bounce higher than the pink ball and has the fastest move speed, but is easily pushed around by wind.
 * Glass ball - Obtained in Markstone Ridgemine. It bounces higher and moves faster than the pink ball, and can pass through lasers, but it shatters if it hits solid ground or walls at high speeds.
 * Yoga ball - Obtained in Utopioca. It can bounce slightly higher than the pink ball, and it falls slightly slower than the other ball materials. It is also used to unlock the teleporter to The Lunar Cheese Extraction Facility.
 * Pathetic ball - Obtained in Crystal Path. It has the lowest bounce height and is the slowest ball material in the game, but the tiger guarding Dr. Cliché's Underwater Lab won't try to eat it.
 * Rubber ball - Obtained in The Lunar Cheese Extraction Facility. It has the largest bounce height in the game by far, being able to bounce twice as high as the Yoga ball.
 * Ice ball - Obtained in Shadowlands. It is the only ball material that can be used in The Future.
 * Ball of Ascent - Obtained in The far side of Ilune Lake. When using this ball material, the player may press the up arrow key repeatedly in order to fly.

Secrets
Deep Forest includes 3 secret mini-games, accessible via the Secret Levels.exe application after they have been unlocked by entering the corresponding 4-digit codes in the final level of the main game, or with a cheat. The games are:
 * Dodgesquare - The player controls a smiley face that can be moved in 8 directions with the arrow keys. The player is confined to a small area in the center of the screen and has to dodge other faces coming in from the edges of the screen. The faces are eliminated when they collide with each other. An ever-incrementing counter in the corner determines the player's score based on how long they survived.
 * Pop - A pointy star spins around the mouse cursor and is used to pop differently-colored balloons flying up from the bottom. The player is given a limited amount of time to amass a high score by popping as many balloons as they can before the game ends. Special balloons marked with skulls-and-crossbones deduct from the score when popped and may cause the score to go below zero.
 * Hidden - This hidden game becomes accessible after the player has activated both Dodgesquare and Pop. The player controls a firefly that can be freely flown around via the arrow keys through a nighttime landscape similar to Pinewood Heights. This game showcases many creatures designed by Sara Sandberg that weren't included in the main game.

Reception
James Murff from BigDownload.com highlighted Nygren's minimalist sound and graphics, and praised its sense of frustration and emotion, calling Deep Forest a "freeware classic on par with the big names. Its developer knows exactly what he is doing, and crafted an excellent, incredibly hard platforming game that stirs right to the soul."

JayIsGames.com has a rating of 4.8 out of 5 for Deep Forest, with a review by Hunty citing "a delightfully whimsical little world filled with the most frustrating jumping puzzles known to man" and that "the cuteness goes a long way toward compensating for the frustration."

Guides

 * Detailed walkthrough by Ghin
 * Abridged walkthrough by Oddity at JayIsGames.com