The Half-Life games doesn't quite hold up to modern First-Person Shooters

F.E.A.R 2: Project Origin, Bioshock, Halo 3...

They all tell the story in a movie-like format. The gun play is also much better and more dynamic.

Here's a list of ideas that the Half-Life series could really benefit from...

• 4 weapon limit (F.E.A.R 2: Project Origin, Far Cry)

• Regenerate health (Halo 3)

• Arms visible when climbing ladders

• Lean ability

• Using guns as melee