Okay, I had a sleep on it, went out to dismantle a mate's laptop, and when I came back...
[color=008000]BING!![/color][/b]
The answer was obvious.
:oops: :oops:
Edit: @ Doobs
I feel a bit better, 'cos number 23 didn't give me any trouble. Must just be a matter of perspective. I bet you have finished the game by now.
Okay, it seems the last levels aren't difficult.
Finally (in other words bollox to level 16!)