Very hard, good concept
Yeah, level 2 is a beast. It's doable if you pay careful attention to placement and juggle your customers, making them use up all their money so that you get the +1000 bonus at the end of the level (on my 3rd try, I beat it a few moments after the start of the last day)
Started level 3, I feel like I'm going to cry. You should create lower quality levels if it'll help to beat the lag.