???Mascarpone, 30 bytes, cracked by Sp3000
[!dlroW ,olleH]$.............
Stack-based? Maybe...
[!dlroW ,olleH]
pushes all of those characters to the stack (yes, including the delimiters); $
pops the ]
; and then the .
each print one character. The program exits with a [
character still on the stack.
I would have made the output use a loop, but I can't figure out how they work...