good news: theres a bypass to run old apps blocked by android 14 for being too old (targetting versions older than like Nougat or Marshmellow causes this)
Slightly irritating: It requires PC adb since the flag isnt present on the device shell.
"adb install --bypass-low-target-sdk-block"
this wont fix possible compatability issues but it will allow you to install the app without being stopped by the new restriction
obviously Wyvern (the latest DU project they're working on, its got Akai Katana Shin sword mechanics its kinda slick) probably has top priority but it would be nice to be able to actually support the dev outside of buying the pc and console releases
Goo Truther 
@lyncia there is a magisk module you can load with root to bypass it untethered.
@thufie i dont have access to root on my device or id probably have used it
someone page Sunny Tam and tell them they need to update the Danmaku Unlimited games on android at some point, because Google Play is now hiding them from view for being too old