When it comes to the Gameboy, It's far less powerful and less memory than the Nes or Snes, so instantly I saw a speed issue here where it feels twice as slow as a regular Mario game. However once you get used to that, it's not that bad of a new version of Super Mario World.
This time around Mario is not taking on King Kooper to rescue the princess, he's collecting 6 coins to enter Warios castle to defeat him. No Yoshi tho.
You take on a map of various zones and complete about 4 stages in each zone to face a boss and collect one of the 6 coins.
It's very short, I managed to complete the game in about an hour or so. It's not all that challenging, but it's not that bad.
This time around Mario can get the usual power ups, plus a bunny ears thing to fly that's a little different to the Cape or feather of Mario 3 and 4.
I found the music to be a bit annoying, I'll be surprised if it was Koji Kondo who scored this game. If not, it needed him.
Overall, had I owned this back in the day, it mightve been repayable having a limited choice of games owned, but by today's standards there's nothing really to urge me to play again. Tho a remastered version in 3D would be cool. Who knows, we might see an enhanced version of this one day? Perhaps a Gameboy version of the Mario Collection made into an All-Stars type of thing with modern graphics?