The game was developed by Tiertex Studios in 1991 at the request of video game publisher US Gold. Development started shortly after the release of the original Sonic the Hedgehog on the Sega Mega Drive.
This is the main hub through which the rest of the game is accessed. There are three places to go from here: the options menu, the main levels and the minigames. The options menu, represented by a yellow question mark, allows for the adjustment of the game's controls and various aspects of its difficulty. There are a few interactive objects that can be used to access other areas; these include springs, helicopters and a hot air balloon. There are also gates scattered about, which block progression until a enough levels have been cleared.
There are over 15 levels in the game. Each level presents the player with a series of timed problems to solve, and is staged as a race; solve the problem and Sonic moves forward some, but run out of time on the problem or answer incorrectly and the player's opponent moves forward. The per-question timer mentioned above is affected by the speed setting, which can be changed from the options menu. The lowest setting is "snail", which gives the player the most lenient time limits and is represented by Sonic racing a Moto Bug. The highest setting is "Sonic", which gives the player the strictest time limits and is represented by Sonic racing a rabbit.
Most levels involve word puzzles, in which the player must spell out a word from a set of scrambled letters. These levels are represented in the World Map by icons which hint at the category of that set of words (such as a cooked turkey for food, or a tiger's face for wild animals).
Other levels require solving mathematical equations by selecting the answer from a set of several choices. These levels are represented by chalkboards; each one has a mathematical symbol drawn on it, indicating which of the four main operations (addition, subtraction, multiplication, division) will be covered in that level.
These levels are sometimes interrupted by puzzles which rely on reaction time. This consists of a window containing a set of numbers or letters which gets replaced with a new set roughly every half second. Above this is an instruction to press fire when a set comes onscreen which meets a certain description; such as containing two or more of the same letter, or all numbers in the set being a multiples of a certain number, among others.
Three minigames are also accessible, represented by clusters of balloons. All of them have a time limit and a scoring system.
|Balloon||In this minigame, the player controls Sonic as he rolls across the ground. The goal is to pop a balloon as it passes by. The minigame is somewhat buggy, however, as sometimes balloons will pop for no apparent reason.|
|Trampoline||In this minigame, the player controls a moving trampoline as Sonic jumps on it and moves to the right automatically. The goal is to help Sonic reach the other side of the screen without falling off the bottom.|
|Green Hill Mini-game||In this game Sonic runs sideways and must jump to avoid debris littered on the ground.
Two different buttons are used in this game: one button is used for full screen jump, and the other is used for a much shorter jump.
Also, there are balloons in the air which the player can pop by jumping into, worth 100 points each.