This was kind of an interesting read regarding microtransactions:
"As such, Thatgamecompany spent two years in the middle of development prototyping business models for Sky, which was originally designed as a premium title. The studio soon realised there was no way they could make a profit and sustain the business by charging for a game in the free-to-play dominated mobile market. This meant seeking an alternative, but Chen was all too aware of the growing scrutiny around monetisation in games.
"The most successful models are very predatory and aggressive," he says. "The other type of gacha monetisation is very much like gambling... Parents don't want to see their kids throwing dice and pulling gachas, they don't want to see people fighting each other." "
" "The more I played these games, the more I felt like the developer was like an arms dealer," he [Jenova Chen] says. "They're selling weapons for whoever wants to pay to win. The conflict is what drives spending. That's definitely something I don't want to associate with."