@schtolteheim it is, the puzzles get *too* devious later on. Which was a major complaint when we were making it but I was too stubborn to really address the issue except by designing a bunch of easier levels and shoving them in, too.
@ShineSpark88 in case you're wondering, Specsavers are doing two pairs of glasses for the price on one in the UK. I suggest you invest in some so that you can see properly.
I'd pay $10 for it happily.