Serious Sam 3: BFE

BFE (possibly) stands for Before First Encounter. The game takes place before Serious Sam: The First Encounter.

Voice Acting Remnants
Croteam were a little careless with cleaning up their work-in-progress stuff from cleaning up, altering and editing the voice recordings for Sam.

Source Audio
A single source recording, from before Croteam had digitally lowered Sam's vocal pitch, is present in All_02.gro\Content\SeriousSam3\Locales\enu\VO_Sources\20110613_Sam\OneLiners\Sam_OS_Mastered\A-G\

Rough Edit
All_01.gro contains rough edits for Sam's voice clips for several levels. These are overwritten in other, more recent .gro files at game load.

Anti-Piracy
Serious Sam 3 employs a variety of amusing and/or annoying copy-protection methods if it detects that it's been cracked.

Digital Rights Scorpion
e91q5BtlxK0 Upon collecting the Pistol in the very first level, you'll be met with a Sam-sized, super-fast, immortal version of the Red Arachnoid. If you kill it with cheats, it'll just keep coming back until you reach the museum.

This is the only anti-piracy mechanic that Croteam or Devolver seem to have explicitly talked about, if not in particularly serious terms.

Highway Look-See
8SkK_ogovhk In the fifth level, walking under the highway causes the game to lock the "look up" and "turn to the side" controls on, leaving you staring at the skies running in circles like an idiot. Also, you apparently take more damage.

Crashing
The game will crash after five minutes of play, and will crash during the ending every time. Nice.