Infinite Combo Chain:
In any area where there's a hub with a grinder (Where you toss Redmond in and pull the chain while he gets ground in the gears) you can perform a very interesting glitch.
Start attacking the side of the grinder until Redmond goes into Hyper mode. Then stand in place as Redmond keeps hitting the grinder. You will notice that the Hyper bar stays up at maximum and your combo chain number increases. You can easily get a 1000+ hit combo in 3 minutes or so!
Note: This does not work with the small grinders that just open doors.