Winning freedom from a nearby game park, creatures enter the factory where Mario is visiting his brother Luigi. Both set about removing the invading animals from their platform game world.
The brothers move left and right along the multi-level floors trying to dislodge the turtles, crabs and flies whilst not losing their own footing on the floors, as their sideways momentum can carry them over an edge, onto a lower level and into the path of an oncoming beast. But Mario and Luigi can move to higher levels or drop down to lower ones as they choose.
The creatures, their numbers increasing with time, appear from pipes on the top floor, and touching one, or one of the large rotating discs, causes a brother to lose one of his three lives.
Creatures are disabled by jumping up and head-butting the underside of floors which bulge upward. This knocks the pests onto their backs when they can then be kicked to the ground below, otherwise they recover and can knock the brothers off. Be careful however, a second thump can right them and once more they set off. The POW marker on the first floor can be used to stun all creatures on screen, so they can be kicked off cleanly. With all of the creatures removed, the next screen is reached. There's an extra life earned for reaching 30,000 points.
'Compelling platform games are few and far between these days which is strange as most games on the Spectrum a few Leers ago were of this format. Mario Bros could have easily been very good, so it's a pity that it isn't. Generally the whole game seems to lack the polish of a completed product - front end excluded. The graphics are simple but sloppy - porky characters are a nice idea but they've been badly defined so they look messy and the platforms, are merely platforms. A few more sound effects during the game wouldn't go amiss as they'd add a lot of much needed atmosphere.'
'I had no fun playing Mario Bros whatsoever. The game is just so terribly boring. All the screens are of the same basic layout, and once you've found the 'safe 'place it holds no more challenge. The graphics are badly and unimaginatively drawn. Playability is poor, and further limited by terrible collision detection. This isn't a patch on the arcade version. Your hard earned pennies would be better spent elsewhere.'
'I couldn't believe how simple this game was; I couldn't find any plot, and I've yet to see more concise instructions. I was expecting, consequently, one of those games whose attraction lies in its simplicity; I suppose that applies to Mario Bros to an extent, but there isn't all that much attraction anyway! The graphics aren't very bad, but the characters look squashed, and the turtles are a bit chunky; colour isn't used that well, either. Overall, not bad, but for eight quid, I expect a good deal more than a simple platform game.'