This game is quite tedious. Faster transitions in the menus (I'm looking at you, end of day screen!) and a way to skip the order phase (that screen is quite painful .. don't forget that we already get recap tickets!), would go a long way in the right direction to make a great game, imo.
Imho, this series would benefit from an "inventory panel" available on a side where unused pieces are stored. This note aside, nice level pack, far more challenging than the original.
I have found that Bugzilla is not that hard to defeat, as long as you poison him on the first turn, use bug repellant whenever it runs off, and always use the Attack 1 of the Alien Gun (highest damage with 90% accuracy, everything else will miss half of the time -_-). Bring the scientist and the fireman for best results, but not really needed. Use medikits as needed. Don't bother with granades/molotovs/etc.