For many people, playing video games is a way to take a break from the rest of the world. They let you immerse yourself in a completely different environment, whether it be back in time to a Wild West setting, or to a fantasy world of mythical goblins and dragons.

In the 1990s though, when console games were growing bigger and there was more room in the cartridges and on the CDs, developers began adding mini-games. These were fun challenges that usually had no effect on the outcome of the main storyline and could be used to practice using some of the bonus features or to provide more use of a fun mechanic.

Some mini-games were boring and people didn’t pay much attention to them. Others were a hit with fans and even ended up becoming independent games later down the line. Here are some of those mini-games.

Call of Duty – Zombies

Call of Duty is one of the best selling first-person shooter games of all time, with a total of 29 titles released so far. It’s developed a lot over that time, adding new game modes and features as new titles have been released.

One of these additions was Zombies, originally added to the Call of Duty: World at War game. The mode became incredibly popular among fans who enjoyed the different rules and mechanics, which saw players take on waves of attacks from zombies that grew in numbers as each new wave came.

The mode was so popular it was turned into a stand-alone mobile game for iOS in late 2009. The premise of the game remained the same, with players having to survive each new wave of zombies.

A second mobile game was released for iOS and Android two years later, and the zombies mode has been included in most titles since, including the recently launched Call of Duty: Mobile.

Grand Theft Auto – Many

Grand Theft Auto is the leader in open-world gameplay, where players can control their character and make them do just about anything they want. This concept was a little ahead of its time when the first title was released for the PlayStation in 1997, but technology quickly caught up and by Grand Theft Auto III, which hit shelves in 2001, it was a huge success.

The open-world model is packed with minigames, from illegal street racing to vehicle missions (where you drive around delivering pizzas), to vigilante justice, putting out fires, ferrying patients to the hospital, and working as a taxi driver.

In Grand Theft Auto San Andreas, they added many new minigames including casino games like roulette and even betting on sports like horse racing. The mechanics are similar to real sports betting like those you’d find on sites such as Oddschecker, although the horses have been given comical names.

In the latest title, Grand Theft Auto V, Rockstar Games took the open-world to a whole new level. While it has retained many of the mini-games found in previous releases, it’s added new mechanisms for interacting with the world. Players can invest in stocks and shares, and they’ll make or lose money depending on the actions they take in the game. This has led to “pump and dump” schemes, which are illegal in the real world.

Driver – Driving Games

The driver was one of the best games released for the PlayStation. It offered some of the open-world elements found in Grand Theft Auto, but without weapons or getting out of the car.

Aside from its “Undercover” mode, which was the main storyline mode, players could try their hand at the different “Driving Games” included. They were mostly cops and robbers themed, with players either chasing another car and attempting to disable it, or running away from the police.

The craziest of these was “Survival”, which was almost like Call of Duty’s zombie mode but in a car. You had to escape from an ever-increasing number of police cars, who would be intent on crashing into you as hard as possible. Surviving just a couple of minutes is difficult without a lot of practice, and you’d often end up having your car thrown across the street or flung into the air.