This is a shellcoding challenge, reversing the binary reveals that the shellcode must be a sequence of notes. A note is a string of the form A0 or A#0, where A can be any letter between A and G and 0 is a digit between 0 and 9.

The shellcode is mapped at the fixed address 0x60606000 (RWX segment), and an int 80h is appended at the end that we do not need to generate ourselves. Registers are cleared with exception of ESI, EDI, ESP which all point to the stack and ECX which is set to 1.