We did do some basic testing and preproduction on animations, so it’s not that this isn’t something we ever thought about. (Warning, low quality GIF, the actual test animation is better than this.)
However, we decided that it’s just not in the scope of this project, and it’s not only a financial consideration, though that would be a factor, too. While obviously web games can and often do have animations, animations at reasonable levels of quality are heavy and when you’re dealing with limited MBs of bandwidth and server space, I just feel its a better use of our resources to just have a lot of CGs rather than trying to animate some of them.
Never say never, but for now our focus is on having a ton of varied artwork. It’s a similar situation to when people really want to have more character customization: it’d be awesome to give players more body shapes and stuff, but that also makes outfits and sex CGs harder. One design consideration can functionally limit another one. Animations are like that; the time, manpower, and web bandwidth, we use to make animations could instead go to making a dozen static CGs.
If I ever do make a game that has animations in distant the future, I’ll probably just go all the way and make a game with real-time 3D graphics, or at the very least I’d leverage something like Live2D and make it in a non-web-based game engine.