I stopped playing Metro after about 2-3 hours, is it worth carrying on?
Yup, although it keeps crashing on Chapter 4 for me, so it's unplayable, tried everything to fix it.

I stopped playing Metro after about 2-3 hours, is it worth carrying on?
Crysis 2 uses a better engine that is capable of much better graphics but is not used to its full potential.
However Metro has better graphics.
This just shows what Cry Engine 2 can do