This is addictive! This had a really satisfying engine-building system. There is some luck to it, but it seems like most runs can still be reasonably successful if you adapt to the options you're given. At first the wisps didn't feel worth it, but once I got a good run with a lot of machines I realized I never would have kept up otherwise lol. I like the washing machine spin cycle and the world exploding consequence for the theme. The music set a good vibe for the game and the dings from the washers were a good fit. I really enjoyed this.
If I had to nitpick, a couple rounds I accidentally bought washing machines and forgot to place them before going on to the next round and then they were just gone. That's definitely user error, but could be worth considering a check for that and popping up some kind of "are you sure?" message as a protect the player from themself kind of thing.