20 em 1 (translated as 20 in 1) is a collection of 20 original games developed and published by Brazilian company Tectoy for the Sega Master System.
The cartridge was only sold bundled with a certain version of Tectoy's Master System III Compact, and as such had no box of its own and was never sold outside Brazil. The games included in the collection were made for children and are relatively basic, ranging from driving to platformers to shoot-'em-ups. None of the games have been named, being only identified by numbers.
All of the games give you 60 seconds to reach a certain score, which varies from game to game. In most of the games the only buttons available are and , which move the character to the respective direction, but some games allow you to perform an action, such as jumping or shooting, with button or button .
You are a construction worker who has to catch tools, which fall vertically from the top of the screen, using a bucket.
You control a hungry lunar creature, that needs to collect pieces of cake and burgers while avoiding explosive obstacles, which will decrease your score if touched. On this game the screen scrolls both to the right and to the left, and every time it is done the items and obstacles on the floor change. You can also use the and buttons, while moving horizontally.
You are a skateboarder boy who earns points by just moving forward and loses points when you touch the obstacles. The button is used for braking, and the and buttons can only be used if the character is moving forward.
You control an odd creature and do not face any enemies or obstacles, and the only buttons available are and , which is used to jump. The screen scrolls, very slowly, to the right and you only need to move fast enough to finish the game.
You are a little mouse who can move horizontally and jump with button . The goal is to catch pieces of cheese which fall diagonally from the top.
It is very similar to Game 01, but you are a diver who must catch coins, which fall horizontally from the top. Another difference is the presence of a shark, that shows up occasionally and makes your score go down if touched.
You control a biker from a top-down perspective and must simply go through the way avoiding the (very few) obstacles. button is used to accelerate, and you can go to the and to the , while in movement.
You drive a yellow car that can be moved to any direction around the screen. You earn points by just avoiding the other cars which appear on the screen trying to hit you.
You are a Brazilian native boy, guiding a canoe on a river. The goal is to dodge the rocks, alligators and flying arrows on the way.
You control a helicopter from a top-down perspective, like in Game 07, and earn points by shooting a rival helicopter with button . When either helicopters get hit they become invulnerable and cannot move for a few seconds. This game allows you to move to any directions, diagonals inclusive.
You are a frog on the surface of a lake, with three lilypads on which you can jump. The goal is to catch bugs which fall vertically from the top of the screen, and to do so you must move to the and to the , and press to put your tongue out. You lose a point if a bug touches you.
You control a spaceship that can move to any directions around the screen. is used to shoot enemy spaceships and other strange objects, and you lose points when hit.
You control an airplane that can accelerate with button, decelerate with button and shoot with button . The goal is to shoot hot air balloons which appear vertically from the bottom of the screen, and dodge other airplanes which, occasionally, come from the left.
It is basically the same as Game 03, but you are a roller skater instead of a skateboarder, and the scenario is slightly different.
You are a baker and must put two cookies into a furnace. Button is used to throw a cookie, starting a Pong-like game on which the cookie bounces off the right side and comes back at you, and you can hit it back with a pan.
You control an odd superhero-looking insecticide sprayer who can jump to the and to the . You must the kill insects which come from the top of the screen, using button to spray on them.
You are a little guy who can move to the , jump with the button and attack the enemies with button . The enemies come running at you but cannot jump, being no challenge at all.
You control a snow skier on a very short course. To control the skier you must hold the button and press the and buttons.
Similar to Game 08, you control a police car and must dodge red cars which try to hit you. You are allowed to move to any directions around the screen.
Another Pong-like game, but in a tennis scenario. releases a tennis ball that bounces off the wall on the right side, coming back at you and you must hit it back with your tennis racket.