Polytopia (Civilization-light, unbelievably addictive) is great on a large tablet. It was mindblowing to play it on a humongous 40" touchscreen I connected my phone to via a docking station - but it's still neat on a 10" tablet and even on a normal phone. The larger the screen, the better the experience though.
Another game that works extremely well on tablets is The Room, a highly polished mystery puzzle series. It's remarkable how natural it feels, with touch and motion controls being absolutely perfect for the types of interactions it offers. The PC port, while visually superior, is actually the less ideal way of playing it.
That's not how this works. The film studio rents the license to a publisher, who then tasks a studio with the development of the game. The publisher in question here specializes in these deals to the point that their website is primarily advertising to rights holders, not customers buying these cheap games (because they aren't doing any research).
It's a lucrative scheme for everyone involved. I've also heard that developing these kinds of low-tier games is often a more relaxed affair, with little overtime and better working conditions compared to more prestigious studios. Low expectations result in low stress.