Is it under-rated though? I'd probably say not, just not so many people visited Efteling goon wise so perhaps not had a wider hit of people waxing lyrical over it...
Plus it's not perfect, given that the touch screens are kinda pointless and the distinct lack of progressing storyline kinda makes a little bit fall flat (same could be said of Dreamflight though really, but as that doesn't present itself to have a storyline, it does get away with it)...