I finally finished the expert run of Mann vs Machine. It was hard until I found a group who focused purely damage (2 heavies, 1 demo, 1 soldier, 1 engineer, 1 scout) and it was my easiest run ever with A+ on all waves except the 4th.
And I also been playing some Xcom. I can say it's a worth sucessor and I really improve over the original. I love some small stuff like having infinite number of the basis stuff like rifles and body armor and not having to bother about equipping ammo on my soldiers every single mission. The solution to base management is charming too.
10/10, would buy an expansion.