Aren't phoenixes broken? I mean you can make a line of them and voila, you got an invincible army. Problem is when this happens with your enemy too though..
There are bugs in the game: my bunker just teleported to the other side of the map, sometimes crates fall and disappear just to fall several seconds later, sometimes grenades disappear during flight and I had a Pak 33 teleport omitting my minefield on the top of the map!