Honestly, Source is a fairly capable engine, and even still, graphics hasn’t been its main selling point since it was first released.
Valve isn’t about “OMGZORZ 5TR1LL10N P0L13Z P3R S3COND PWNIN TEH COMPETITIONZ SUNSHAFTZ N BLOOMZ N SH1NEY EVERYWHEREZ!!!” like 90% of the rest of the games industry is. They specifically worked to make sure Source could scale down REALLY far and have pretty damn low system requirements, and to make up for it, they spend a HELL of a lot of time on art direction, so the way the resources are used ends up resembling life extremely well, and so you don’t even NOTICE it’s not that advanced unless you’re a graphics whore and you’re looking for it.
Also, what are “caustic effects”? Does this thing cause the video card to spew corrosive liquids all over and burn holes in your computer case or something?
[color=black]Also, Myst sucks and has really obtuse puzzles.