@twd Now the 'backup your data' lesson is one we've all learnt the hard way at some point!
I didn't get as far as the purple goo, but I did check out a YouTube play through to see what to expect next, and someone played through with that goo making the ship totally invisible. I thought at the time, there's no way I am going to make it through that! Seemed a bit weird there was then a whole lot more levels (including 'PRO' mode going through them all again!) when I reckoned most people would have run out of credits getting through that purple goo.
The fact it is meant to be transparent makes a lot more sense!