Master of the Monster Lair is anything but impressive visually. The cartoon look has a nice charm, but something about it rubbed me the wrong way. I tend to dig the anime look, but there's a certain sense of character missing from the game. Dungeons are no more compelling visually when you first start as they are when you're finished. Textures are incredibly flat and bland and there's a noticeable lack of color. I understand that the game takes place in a dungeon, but that isn't an excuse for things to look as uninteresting as they do. Even the monsters you lure into your dungeon lean towards the generic side.
Sound follows the lead of the visuals. The music is anything but memorable and becomes annoying a few hours into the game. In a sense, it is like a Coldplay song - it isn't bad, it just isn't something you want to hear on a constant loop.