The 9 Best Actually Free Games on Amazon Underground

'Sonic CD'

Arguably the best Sonic game ever made behind perhaps "Sonic 3," this game is well worth checking out. The game's time-travel component is very well done, as it lets you explore various levels and paths, some of which are obscured in different time periods. Plus, you need to destroy objects in the past to ensure a good future.

There are four different themes and layouts for each level, with past, present, bad future, and good future variations. It's an impressive achievement for a 1993 game, and the port two decades later did a great job at adding small tweaks and refinements to go along with features like widescreen aspect ratio, both Japanese and North American soundtracks, and mobile controller support, to make this the definitive version of the game.

Requires Android 4.2 or higher.

Play Sonic CD

'Goat Simulator: Waste of Space'

Be the first goat in space in this crowdfunding parody. Everything you do can net money that goes toward funding the entire crazy operation, opening up the game, and unlocking features such as spaceship battles. Seriously. It's a mockery of crowdfunding shenanigans that some modern games employ. The game promises to teach you to be a real bridge commander "like that Spock dude." You'll be able to shoot down asteroids and space pirates, build your own space museum, or fly your own spaceship.

Requires Android 4.0.3 or higher.

Play Goat Simulator: Waste of Space

'Farming Simulator 2014'

The aforementioned "Goat Simulator" game started off as a parody of simulator games before moving into mocking other game genres through ragdoll goat physics. What if you prefer to judge those simulators for yourself? Well, a mobile version of "Farming Simulator 2014" is available for your perusal, allowing you to experience the joy of farming. Modern farming involves piloting a lot more heavy equipment than you'd expect. It's an acquired taste, but you might like it.

Requires Android 2.3.3 or higher.

Play Farming Simulator 2014

'Star Wars: Knights of the Old Republic'

"Star Wars: Knights of the Old Republic" might be the best bargain you can possibly get on Amazon Underground in terms of the actual cost of the game, the time you can spend playing it, and perceived value. BioWare rose to prominence with this role-playing game, taking place centuries before the original "Star Wars" movies. Its morality system laid the ground for countless other games to implement similar systems, including having a major effect on the ending of the game. Plus, it made "Dungeons and Dragons" accessible by putting it in a "Star Wars" wrapper with 3D visuals. It's still a solid RPG to this day and provides dozens of hours of entertainment. If you can nab it for free, that's a steal for one of the best RPGs on Android.

Requires Android 4.1 or higher.

Play Star Wars: Knights of the Old Republic

'Heads Up 1 Against All'

The "Heads Up 1 Against All" party game, inspired by Ellen DeGeneres, is goofy but certainly worth the low cost if you can't score the free version. It comes with a ton of no-cost add-ons. The gameplay is simple. Just put your device on your head and start the game. Tilt your device down when you guess correctly and up when you want to pass.

Requires Android 2.3 or higher.

Play Heads Up 1 Against All

'Jetpack Joyride'

"Jetpack Joyride" offers a silly take on the Flash helicopter game, where you dodge lasers while using a bullet-firing jetpack. It's still a rather fresh game despite being several years old. Of course, it has the grinding for coins that can make getting those great customizations a challenge. The Amazon Underground version includes tons of coins at no charge, so you can just play the game with the customizations and boosts of your choice without having to pay. The non-Underground version is free to download but is full of in-app purchase opportunities.

Requires Android 4.1 or later.

Play Jetpack Joyride

'Badland'

This game was always a try-before-you-buy model, where different level packs were available as in-app purchases. This one-touch flapping platformer gives you tons of challenges to tackle, with a stylish shadowy visual theme. It's a gorgeous game and is a well-made platformer that's perfect for mobile. The 100+ levels are available in single player and cooperative mode for up to four players.

Requires Android 4.0.3 or higher.

Play Badland

'Monument Valley'

This gorgeous puzzle is already one of the most popular paid games in the history of mobile gaming, and there's no reason you shouldn't already own it. Perhaps you were late to the party or wanted to check out the downloadable content that was released later. Play as main character Ida as she makes her way through a series of puzzles that are optical illusions. This is a glorious experience many other games have tried to replicate, but few have come close to nailing what this Escher-inspired puzzler did in terms of style.

Requires Android 2.3.3

Play Monument Valley