Wonder Boy is an action-platforming game where you have to advance through levels rife with enemies and pits while on a timer only refillable with some nifty food along the way. It is the first game in the Wonder Boy series and has the same gameplay as Adventure Island on the NES.
I don't think that this game is bad. However, I also don't think that the gameplay is especially engaging either. It is pretty average and honestly eclipsed by the plethora of amazing platformers on the Sega Master System. That being said, it may still be worth checking out if you are curious where the Wonder Boy series started or if you have played the Adventure Island series and really find that type of gameplay engaging.