Serious sam second encounter question

[FredLocks]

there is a secret room on the first level with letters on the floor, some are lit up....i can't figure out what the secret is to the room....is there one.
Also, what the heck is that secret telephone booth at the start of the game?

Thanks

 

[DARRIN]

The 6 letters can be arranged to spell MENTAL. Took me half an hour to figure that out. You have to jump on them in order. Then you get a little treat.

 

[FredLocks]

thanks darrin.......