Fun game, the truck feels really good to control. I liked taking advantage of the change in physics with helium and navigating multiple trucks through the enclosed pipes at the same time.
I feel the main loop gimmick was a bit lackluster due to the unpredictability of when a replay would happen. Maybe it'd be better to sync and start every trip whenever any package is picked up? Would somewhat break the idea that this is a constant delivery stream though.
Could also use some arrows to guide the player to locations to pick up / drop off packages. I spent a fair amount of time trying to figure out how to get the game to start because I didn't realise there were other packages that could be delivered...