So while there's no official remake of Wonder Boy in Monster Land, I've recently discovered the awesome news that someone over at the SMS power forums is doing a fan remake and expansion of the game calling it 'Monsterland Meka', looks like it also includes stuff from WB1 (skateboard) and WB5 (player home) too. It's early days so far but I love the backgrounds! Entire valleys of grass, flowers, forests, & rivers surrounded by mountains. Love the music remasters too! The 3D main character appearance and animation leave a lot to be desired though lol, but its creator Immo has told me that it's just a placeholder until proper 2D animating art work is drawn over the top of it (similar to some of the 2D snake baddies already done).
Video:
https://www.youtube.com/watch?v=CARpsl0NpuM
There's a gazillion pictures on his website but here's some of my favourites:




