The Hot Air series is a series of three adventure avoider games produced by Nitrome, on the adventures of a hot air balloon named Hot Air. The objective of the game is to guide the balloon from a starting point to an ending point using a cyan fan, while avoiding obstacles along the journey.
Each installment is divided into levels. In each level, the player has to guide Hot Air from the launching green pad, to the landing red pad, by using a fan to blow Hot Air along. In this process, the player has to circumvent various obstacles, upon which the balloon will pop on contact.
There are numerous stars scattered throughout the level. Should all the stars in a level be collected before landing Hot Air on the red pad, one would earn a star token for that level.
The levels have a two-dimensional design.
Upon activation, the fan blows on the balloon,exerting a force on the envelope of the balloon. The direction in which this force acts on is dependent on the position of the fan relative to the balloon. This direction can be deduced by tracing a line from the fan through the centre of the envelope.
The acceleration which the force produces is inversely proportional to the distance from the fan to the centre of the envelope. That is, the closer the fan is to the balloon, the faster the balloon would accelerate.
Hot Air was released in 2005, and was Nitrome's first flash game. It followed no plot, and it's levels were presented in a simple grid. Much of the later levels of Hot Air are unlockable levels, opened by collecting all of the stars in a certain amount of levels.
Hot Air 2 is Nitrome's first sequel published in 2007. In this game, Hot Air travels off to rescue his girlfriend, who has been captured by the evil Baron von Blimp. In this game, the player could earn new skins for Hot Air!, and could also make them with the Hot Air Balloon Maker until it's downfall.
Hot Air Jr. is a sequel that was released after a five year break for the series. Unlike the previous titles, the main character is Hot Air's son. Hot Air Jr. must rescue his dog, Squeak, from the giant spike ball, who captured it. A demo for Hot Air Jr. was released prior to the release of Hot Air Jr, this demo containing a few rooms, enemies, and stars to collect.
This tool allowed the players to make and submit their own balloon designs. The designs could be used in Hot Air 2. But, as of March 5th 2009, Nitrome discontinued Hot Air Balloon Maker because the amount of balloons was too great to switch to the new server and that a lot of them were obscene. Ten million balloons were made in its lifetime.