Blu2th1000Things that are broken that I've tested:
P-Rec (RIP)
Lawena
HLAE (Most likely to get fixed, already reached out about it)
SVR
DXLevel 81 (WTF)
Things that are NOT broken:
Demos from July 26th Onward
HLAE still works somewhat for 32-bit, but you must launch tf.exe and NOT tf_win64.exe.
Features like AGR will be stable again after my patches are accepted and released:
https://github.com/advancedfx/advancedfx/pull/929
(The latest patch is now released, and should fix all known issues)
A 64-bit port will likely never happen, or it will take a very long time.