Fairly simple achievement. You only need to finish the last level of an episode to get the achievement and you can cheat.
So start a new game > Alien World Order > Hollywood Inferno
Now press Down, X, click RS, right to open the cheat menu. Turn on God Mode and Give All.
Now select your jet pack and fly up to the Hollywood sign. If the big red boss doesn't spawn, you can force him to spawn by falling into the hole between the L and the Y and fly back out and he'll spawn. Kill him and the achievement is yours.