i bought some mann up tickets yesterday and just spent the past 4 hours grinding the first mission on decoy
shit was hard as nails, especially the later waves but even then the final wave was as hard as even harder nails.
but, the ragtag group of people i was with managed to persevere. i swear we put at least 1+ hours in solely for the last wave. we had a demo, an engie, a spy, heavy, kritz medic and a pyro, a reasonable team comp but we still wiped so many times until we lucked out with second tank as we got it when it was milliseconds from blowing up