Go compare the graphics of HL2 to any AAA titles that came out the last few years, you'll be flat out lying if you say HL looks better
On your last statement. The problem with 1st person platformers is that you can't see your feet. At the very least, a 1st/3rd toggle would have been nice.
The only parts that hinge on the 1st person are some of the story elements, which are thin to begin with.
