This was the last port to finish?
I think so. Only missing one? The Plus/4 which doesn't provide codes so you have to finish them in one time. But using savestates can help? I'll try to see if it works.
No, but it has a level-skip feature, so you can quickly get back to any level.
I noticed this. But I think it is like a "cheat" key in some ways :)Anyway, using Yape - and save states to play all the levels a few at a time - I made it to the end for Tenebra. Without using skip level key :)