Are there good sites for discovering these sorts of games? In the category of retro-style games for mobile platforms, it's an enormous chore to find anything good by just paging through the app stores.
I personally prefer retro on the older machines. One can play and code via emulation, which is quite good these days, or get some older gear and go that route.
Both work for me. I enjoy the real gear for those machines I am familiar with and own. (Apple ][, Atari 8 bit, CoCo) Emulation is great for others.
Emulation is good for coding either way. We get modern tools. There is a fun experience to be had working right on the hardware, but it's hard to put in the time. Emulation helps a lot with that.
The other path is to visit sites and forums that focus on older hardware. New productions are frequent, emulation good, help at the ready.