This game is a great classic! It is, for me, The Best 2D Platformer of All Time!!! It's ALOT better than Mario!!!
There is Master Higgins, sleeping very well in his island, until those god damn aliens kidnapped his girlfriend. It's up to him to go in this crazy archipelago, filled of monsters and traps, to stop him from reaching the end... This seems like an ordinary game, right? But the fun that you'll get by passing the levels shooting hammers at enemies, using dinossaurs to help you out, defeating the bosses, jumping your way until the end of the game and earing one of the best NES soundtracks ever, is just incredible.
The game is quite challenging! I have never completed it, but I'm still trying and hoping for one day to see the end of this amazing game...god I miss the 80's :(
In overral, chances are that you'll prefer Super Mario, but in my opinion, this game is much more fun. It's bigger, more challenging and is, simply, One of The Best Nintendo Entertainment System Games of All Time!!!