It’s also worth noting that in the case of games in Japanese, it’s not so easy for developers to find alternatives. While games using English can rely on system UI fonts, cheap commercial fonts or open-source options, the sheer number of characters used in Japanese means high-quality fonts are extremely difficult and expensive to make, so few affordable alternatives are available.
I’m guessing the problem is they want a relatively unique font to avoid looking the same as other games, and then once they’ve chosen their font they’re pretty much stuck with it unless they’re willing to change the look of their game (for live-service games at least). A number of the fonts there might work for new stuff though.
Yes, you can use them commercially, and even include them within a product that is sold commercially. Usage and redistribution conditions are specified in the license. The most common license is the SIL Open Font License. Some fonts are under the Apache license or Ubuntu Font License. You can redistribute open source fonts according to those conditions.
There’s already a decent selection of high quality, freely available Japanese fonts here: https://fonts.google.com/?lang=ja_Jpan
I’m guessing the problem is they want a relatively unique font to avoid looking the same as other games, and then once they’ve chosen their font they’re pretty much stuck with it unless they’re willing to change the look of their game (for live-service games at least). A number of the fonts there might work for new stuff though.
Free for commercial use?
Yeah:
https://developers.google.com/fonts/faq#can_i_use_any_font_in_a_commercial_product