I’m not a big fan of this. I have nothing against free-to-play or pay-to-play games, but you have to know that going into the design, or it feels cumbersome.
Unfortunately, if you do IAP on iOS or Android, you have to write all the code to make the purchase. This is unlike Steam/GOG where you buy the DLC from them, and it’s just downloaded. Writing store code is a PITA, I’d like to avoid it if possible.
It would be possible to have a demo that you can play for free, then pay to unlock the rest of the game. As others have mentioned, you have to be careful or you’ll get backlash. You also have to have a point in the game where it feels like a cliffhanger that players want to know more about, but also not give them too much play time. I don’t know if TWP has a moment that satisfies both of those. Maybe one of the agents getting knocked out, but that’s optional. Maybe end the demo after they complete the first flashback.
Before doing something like this, I want to see similar games where this succeeded. I know of a lot where this failed, but that might have just been the game, and not the model. 50,000 installs/downloads is not a very interesting number. 50,000 purchases is, but conversion rates are in the 5-10% range (even lower for traditional free-to-play)