Mario Bros. is an arcade original ported to the NES, Game Boy Advance, and even the 3DS as a part of its ambassador program. It was one of the earlier games actually developed by Shigeru Miyamoto and then again by Nintendo in 1983. The story of the game is very early Mario; it's simply Mario and Luigi flipping unwanted creatures in the sewers on their backs through the POW Blocks or from a platform below, and then kicking them away from the screen before they recover and return again.
I was first introduced to this game a long time ago, because it was part of Super Mario Advance, really my only enjoyable game for the Game Boy Advance.
I report that I was way better with this game on my GBA than on the NES, but the NES version is roughly the same and I sort of got the hang of it.
There is very little I dislike about the GBA version; it has simple controls, better graphics, and the same style of gameplay, only executed better. I could get through a whole lot of stages in that game, it's a shame I lost my GBA (sadness!).
One thing about this game that I think is enjoyable and clever is the fact that you can run off of one side of the screen and come out the other side. This applies to everyone and everything, and it adds a tactical element, with a lot of skill in prediction. That is, you have to decide what to do if two enemies are heading towards each other near one side of the screen, and are about to bounce in different directions. What's more is that some of the enemies move faster than others, and require multiple hits to flip over on their backs, so you have to be quick and precise even in the earlier stages.
To be quite honest, I think that is just great, because I'm always disappointed in simple games that aren't challenging at all until you get to level 10 or whatever. In this game, the intensity starts at level 3 or 4, so you won't be bored for very long for those of you who like fast-paced, mental, reflexive challenges.
On the GBA especially, there are virtually no complaints I have about this game. On the NES, the controls are a little strange, because if you jump, you can't move in the air; you have to run a bit first to get to a platform above you.
However, the Game Boy Advance has everything you could want: great controls, lack of monotony (although that's basically in both), and a fun setting. If you can find a way to play the NES version and enjoy it, absolutely buy it for the VC.