In programming point of view. The land mine is possible.
1) Lay land mine, x,y coordinate mark with mine.
2) The xy mark will be attach to each character (alien and soldier).
3) Whenever character is moving, check for the xy mark and current location...if hit....kabooommm.....fly sky high!!!
Another, point...
1) If shoot at the land mine... shouldn't it be blowing as well?
2) If the land mine somehow blow up... what about the "other" land mine that lay next tile? shouldn't they be blowing as well?
3) Currently (as for my understanding) there are no flamable/blowable items on the map... example oil tank, explosive chamical etc....
4) I'm actually looking forward for chain-blow explosive effect....missing it so much... dream for it....