A nice task for implementation, but the description is quite tricky sometimes.

What if Program Counter went out of last instruction? - it is ok, you can think about it as normal termination by END command
Is NOP count towards overall operations count? - no, empty lines and only-label lines do not contribute to the overall number of executed commands
Are labels case sensitive? - no
Are operands case sensitive? - no
Are variable names case sensitive? - yes
What about int32 overflow? - guaranteed that there are no overflows
What about % operation? - the result of A % B operation is such C that 0 <= C < B and exist some integer Q: A = Q * B + C
What if 10_000_000th command is END command? - The end command terminates the program
Can variable name start from digit? - no