There are only lewd scenes. I was thinking about the whole story, all dialogues etc. But, without rpgm.
Not enough story in Treasure of Nadia to make a half-decent Ren'Py that's for sure. Often the plot is disjointed, incoherent and makes little sense because too much detail has been left out to work out what the heck is going on. Characters disappear for long periods on solo adventures, quests and tasks, e.g., Clare and Diana gallivanting off on expeditions looking for treasure and/or TikPak artefacts, eventually returning, out of the blue, with knowledge/items/whatever without relating anything in respect to where they found them, what difficulties they faced, or how they took possession of them: essential elements as per evolution of the story is concerned are frequently omitted, because the game unfolds in the first person from the point of view of the MC, and the MC happened to be absent when they occurred. The dialogue is often forced and stilted, conversations between the characters dull and clipped, and plot chock-a-block with continuity errors, discontinuities and holes. Rip out the role playing and graphic sexual animations and there would be very little left, sad to say, but then the story is only present really to link one animated sex scene to the next in a chained series of increasingly strong and bizarre if not ridiculous hardcore vignettes. That said there are games out there that really do possess great artistic, dramatic and literary merit - the visual novel Summer's Gone being the best example I can think of off the top of my head - but Treasure of Nadia definitely isn't in that league, nowhere near it, and never designed/supposed to be, when all is said and done, if we are being honest.
Treasure of Nadia does exactly what it is supposed to do in respect to the audience it was created to pander to.
(Which is the reason why NLT Media is on its well on its way to 14,000 Patreon supporters. )