ok I got the achievements after a lot of re-doing the levels but have a question for the developers/coders.
in map 3 it says find 5 survivors. I have yet to find more than 4 survivors before the level ends.
each level is very small. some of the requirements may not get met before the level end at present. maybe the level should continue until there are 5 survivors met in level 3 and should be a bit longer if there are others later with similar requirements? I have to admit I have not gone past level 6 yet. spamming lower levels for cash for equipment and experience to be able to use said equipment.
also with reference to earths reply to my post earlier...
a soldier hidden is not a problem as such if you can be sure he is with the rest of the squad but I have found attackers taking lumps out of invisible soldiers who are supposed to have formed the line at the back and seem to be half way into the screen and getting damaged.and this only happens after getting the extra man to the 3 originals.
another issue seems to be that the original 3 will gain wounds from a bomb going off in the house clearances but the last of the squad gets no damage at all.