The invisible markers which show the location of the aliens need to be seriously tweeked! Because I find that even after it dies it sometimes still stays there and you end up wasting very limited ammo on an empty location. Also the colour needs to be different for civilians as you end up shooting them also. While on the topic of “invisible” aliens it is a bit to much to give these aliens both “MIST” and “INVISIBILITY” it needs to be one or the other because they are supper armored as well and take a lot of killing! The mist also needs to fade each round because I have had entire maps full of mist so much so it was UN-playable and needed to restart the mission. What happens is you get 30+ of these creatures all blowing mist and turning invisible and sitting in the mist with high powered sniper rifles taking you out with no hope if shooting them back, just plain annoying!
That is why you need to check what is there. It shouldn’t be tweeked in any of your ways. 
It should be only changed to
- not show exactly at enemy location, and
- only show and stay in places where enemy made some meaniningful sound, like opening the door or breking window or leaping over fence.
Another no. Snapshot should only limit number of these enemies and number of powerful guns they can bring to battle. With limit of 15 Tritons and like 6 Sniper Rifles, 6 Shotguns and rest usual stuff like handguns and assault rifles it would be playable. You wouldn’t have mist all over the map and they wouldn’t be sniping you whole the time. Mist will probably dissipate but definitely not after 1 turn - maybe after 3 or 5? Otherwise it would be not useful to the aliens.
When the alien dies the “marker” does go! However, this is not always the case as sometimes you can stand right next to the marker and it still stays there, so there is a bug in it right now? They really, really need to go when it dies! As for “not show exactly at enemy location” that is just ridiculous is has no purpose then but to make the game harder than it already is! And what would be better is to not “mark” the civilians at all, that would also save you throwing a grenade into a crowd of people your there to save!
You misunderstood my comment about the mist, I said it needs to START dissipating each round (gets less each round) not completely gone in one as you seem to think I said?
Oh, ok. That is strange. Must be that enemy body is realy stealthy. 
It should be fixed.
Sorry then, you are correct. 