Honestly this chapter is worse than previous. More clever NPC and ability to somehow drive alien mecha (probably even without knowing how to drive it) are nice but hardly will impress today.
On the other side, game is overfilled with guns, half of which are never used. If you buy them accidently, it will be hard to switch between two weapons you really need (a knife and any ranged weapon you prefer). Actually you may complete the game buying only flamethrower (fully upgraded, it takes down UFOs with ease). and kill everything else with knife/shotgun.
Other question is supplies. Chapters 1 and 2 were linear and finite, thus we had to count each and every food pack and bullet. At chapter 3 we can leave shelter, re-enter it, recollect supplies, repeat. I won without doing that (too much - of course I used opportunity to re-search each shelter I were in), however with patience can fully upgrade self and store hundred food packs to serve as medcits. This grinding really breaks balance (althrough it is already not a lot of challenge...)
Overall: nice but have some bad things