(If i write not in right forum, so i'm sorry)
((and if somebody alreasy write about it - too sorry))
So, i have found one bug in the City Siege 3: Jungle Siege, in the mission Boom City.
Firstly, take a spy and then rescued all VIPS and CIVS and then come back to start of map.
Then, take MECH (i dnt know if it work with other character) and go to kill them all.
And in the very end of map, there was a blue barrel with gas and barrel with fire. If blow them and make a big explosion then the map will be broken.
The ground will disappear in some place, and the units cant fire anymore. So is so baaad! Only way is just go to menu and play again.
Here is some photos
I try this 5 times, and every time it was like i said.
So, it is unnecessary (optional) to take MECH. This bug may be even if SPY blow them (Stay near barrel, and then when Enemy fire in barrell - jump, or something else.