Well I don't know about games being like Lemony....b/c I've never played it.
And it's hard to recommend challenging adventure games when you say you don't want them to be too hard. But I'll give it a go.
My first choice for you when first seeing this thread was "Shadow of the Colossus", whic happens to be made by the same people who made "Ico", which Phat J recommended above.
The problem is, this game may be very challenging for you. You have to think in this game and figure out puzzles and strategies basically for navigating these Colossi.
Ummm....let's see........."Radiata Knights" may be more you're style. It's an RPG, but it's very toned down when compared to the more Dramatic RPGs. It has many funny moments. More on the comedic side. It's not that hard either. It's a good game though.
Although I haven't played Okami, I would think that'd be a good game as well.
Of course I'll aslo recommend "Final Fantasy X", "Final Fantasy X-2", and "Final Fantasy XII"
And "Kingdom Hearts" and "Kingdom Hearts 2" are 2 very good RPGs. They have challenging parts here and there but are overall very easy to get through.
Well I hope that helps.
anata wa wakarimasu ka.....