Cute! And tons of content considering each tool is like its own minigame! I like how there's a story and a goal, and you have a choice of buying more tools or saving up to pay off the debt. The day end summary was nice as well, especially showing how many days were left. I ended up purchasing the biopsy syringe, scalpel, adenosyl, and needle, though I never ended up using the adenosyl to my knowledge.
I got really into this and played to the end, even though I used all my money on fancy toys instead of paying off my debt ;).
The heartbeat on the patient status was a nice touch, but didn't feel like a key mechanic, since the circle and their faces tells me more at a glance.
I did find it a little hard to understand what was really wanted from me in some of the procedures, like putting the bandage on. Sometimes it'd look not great and like I was missing part of the line, and that would be accepted, and other times it'd yell at me when it looked like the bandage was perfectly aligned and completely covered the wound. Possibly having some kind of positive reinforcement or guide could help here, so it's not just accepted/rejected and you have to figure it out through trial and error.
It also seemed that if two tools were required for a procedure, only dragging one of them onto the patient would work (and which one is "the one" changed from patient to patient for the same procedure), which was a little annoying. I also got stuck a little with some patients just not being able to be interacted with at all. In my case, when they needed the biopsy needle and the scalpel, neither of them would work to bring up the procedure when dragging onto the patient.
Game balance-wise it seemed a little off. Buying new tools didn't seem to increase my money earned, and there were so many tools available, possibly too many for the 7 day game time. The days themselves also seemed a bit long -- one day I was able to see I think 39 patients?
But all-in-all this was a massive undertaking and I had fun :D