The prototype is fine, but it needs a lot of work.

First of all, the UI is just not polished at all. It's a bunch of text, followed by more text, then even more text and options, with the actual "action" at the bottom of the screen. I know it's a prototype, but it's hard to imagine what the final product is going to look like without a proper UI that makes you think, "Oh, that's how the final game is going to be." The first thing I'd do is polish the UI: add styles, panels, icons, and whatever else is needed to make it feel more like an actual game.

Now, about the gameplay: it's very simple, but it becomes unnecessarily complicated. For instance, why do I have to open chests? Why can't I just get the loot directly? There's no reason to get a chest and then have to click a button to open it. Just drop the loot and let me decide whether I want to sell it or equip it.

Also, why do I have to sell the junk? I mean, if you could do something with the junk other than simply getting money for it, it would make sense. Let's say you could use it to craft something. But just getting junk and immediately selling it feels like "getting money with extra steps."

And that's basically the game's main issue. Instead of adding interesting things to do (maybe crafting, researching, or something similar) the game artificially adds pointless tasks and unnecessary extra steps that add nothing of value to the experience. A button to open chests to get loot instead of just getting the loot directly, or a button to sell junk instead of simply getting money when you kill zombies.

What the game needs is real, meaningful mechanics instead of pointless extra steps.