For the first boss, its annoying how once it crumbles, it just blocks everything else which makes it hard to get 6 stars when the parachute pigs fall on either side of it. Either the missiles should go through or some other way of making that boss easier. Overall 5/5
Like all of the Papa games, I think that in the build section, it needs to be able to work on more than just one item at a time. It's frustrating to have your burgers cool down when working on one of them because you're waiting for a customer.
The 'defeat the revenant as different classes' thing, while nice in the crusade, is just dumb here. Unless you really really want those achievements, you're not exactly going to want to finish the game four times.
For the achievements of drinking 100 health and mana potions, maybe put in a counter? Just for people like me who've finished the game without using many and just want to buy as many as necessary for the achievement.