Not that I don't want to entertain the possibility, but I need to level your expectations using plastic explosives of logic and knowledge. This is simply impossible.
You should consider the
"low" specifications of old mobile devices, because unless we're talking Nokia N-Gage, what you think is low-spec is still quite ahead of the Dreamcast. The
first retail Android phone was the HTC Dream in September 2008. Its specs? A 528MHz ARM11 processor, and 192MB of RAM. Even decompiling an APK to get its source code is out of the question, because you'll be stuck with a Java based manifest. There's still no Java virtual machine that exists on Dreamcast, and Android's implementation of Java is fairly specific.
Scale your expectations back a ways. Here's my recommendation
https://github.com/mupfdev/Rifts Released for the N-Gage in 2005, Rifts: Promise of Power is based on the WH40K property, This is just to build a DRM-free version still intended for the N-Gage, but the person behind it was working to port the title to SDL2 (he got hung up on the renderer apparently) which would make it possible to play on a number of devices if it ever comes to pass. If there's any games that could be viable, it's in the N-Gage catalog.