Nice roguelike shooter! It looked great, and I think you had some good ideas here. The core gameplay was pretty difficult, and I'm not totally convinced it's possible to beat day 3, but I think this is only a few minor improvements away from something great! Here's some simple things that I think would improve the experience a bit:
- Clicking directly on the zombies is fairly unintuitive and a bit tedious. I think a more standard "line of sight" collision would make more sense. Clicking right in front or behind a zombie and still missing them feels like a bug when the animation shows you shooting at them with a pistol
- The only upgrade that feels useful is damage. Cooldown upgrades are much too small to make a difference, HP won't save you if the zombies keep piling up from your lack of damage, and the scrap-per-day upgrade takes 4 days to pay off (which is a nearly impossible feat). I would buff the numbers on pretty much all of these
- Add a timer that shows how much longer you need to wait until the next day. Not knowing if there's 5 seconds or 5 minutes of shooting left makes the game drag at times
- Give scrap for killing zombies. This will help the extremely restrictive prices, as well as give you increasing progress for each level. As it is, a zombie is an annoyance, but if it gives money, then it's an opportunity to look forward to
Keep it up! There's definitely a lot of potential here!