I now tested Serious Sam 2nd Encounter on both Buster and Bookwork and I get the exact fps. So 3D acceleration is fine with Bookworm, there must be something wrong within your OS configuration.
Should be debian-security not security-debian.
In case someone still uses buster, follow this to get some more recent packages:
https://pyra-handheld.com/boards/threads/pyra-unofficial-quick-reference.99841/#post-1717237
The entries should now be replaced with "deb...
So finally TWO MONTH has made it's way to the Pyra, which means some bigger files still can be uploaded. What's the exact problem with some files always showing upload failed and other files working?