Context is important here.
A game like Phone Affair is not nearly as demanding as most other RenPy games, especially since there are a significantly fewer renders "required" for a game of this type (very few complicated scenes and lower quantity) because of the format (text chats). I'd even say that the coding is the biggest hurdle in these types of games compared to rendering for them.
True that the renders are few compared to normal renpy games. But the lower quantity is compensated for by the quality and the renders of this game are very high quality and have no doubt it takes a lot of time to make them look that good.
If we compare with normal games, its obvious that most renders are just quick ones, same angles but with different expressions that bump up the total renders count without much attention to details. Most of those renders are for dialogues while in phone games, those renders are just replaced by pure text but include renders for scenes that matter like any hot scenes.
Its easier to create 100 quick renders compared to 10 that is in a different league. But like the dev said, its the different routes that takes up time the most. Its no different than writing 3 stories at the same time. So I would say it is even more demanding than usual renpy games at least in writing.
Considering all this, we will get 2 weeks to 1 month update. So it's pretty fair which is why I said I was surprised.
