well for a start maybe u could add a risk factor like some one could break into the vending machine and reset ur progress but if u add that u'd also have to add a buffer so u dont lose all ur money and have to restart an then maybe an obstacle like bills for the vending machines and i wouldnt make every vending machine unlocked at the start of the game.
Thanks for the suggestions, I really appreciate you taking the time to write all that out! Those are actually some really solid ideas.
I especially like the risk factor you mentioned with bills/expenses for running them. Adding some danger and management pressure like that could make the gameplay loop a lot more exciting towards the beginning. At the moment there are randomized shortly timed events that take place while you play to keep you on your feet and prepared, but I do agree that there needs to be more for the early game.
I'm already experimenting with a few mechanics along those lines for the next update, including more progression and things that can impact your machines over time. Feedback like this really helps shape where the game goes, so seriously thank you for sharing it!
If you think of any other ideas or critiques while playing, feel free to drop them here!