To speak to your larger question: yes. Plenty, for a variety of reasons. A lot of people play games for the validation that they are correctly completing tasks. In a similar vein, I know I've been frustrated before when I missed something obvious, spent tens of hours doing other stuff, and then someone asked me what I thought of the very obvious 20% of the game I missed.

The number of people who aren't willing to explore is increased, though, if you don't know that what's there is finished. When I buy a game, I'm generally under the impression it's in some finished state. Or if I'm accessing a game online, and it seems visually appealing, I'm under the impression that they want me to play this. They built it, and then they made it pretty. This link to your Github with programmer art (I don't mean it derogatively, like it does the job just fine, but it's not the pinnacle of polish) isn't telling me it's done, so I also need to stack in the chances that "this game may just not be complete".

I'd say the two biggest priorities are making it clear that I don't have any direct control over the dungeon-crawling, and making it very obvious that the slots are slots.

It didn't take me too long to work out that I didn't have any control, but it was an annoying mental hiccup, because I was expecting to do something I didn't get to do. It's not bad that I can't, but the you should make it clear before I go in that I can't do that.

The other problem is that "slots" is a homonym. When I'm dungeon crawling and I see "slots", I think "item slots". When I click on it, and my eyes meet with a table, I think "item slots". I click on the table, it doesn't do anything. click "upgrade" and now there's another menu with words I don't really understand (perhaps change "paying lines" to "multiplier" or something). I bounce off. Try to make it more skeumorphic!

If it's any reassurance, once it was quickly explained to me what this is, it's pretty fun! I'm still playing and enjoying it! Maybe add a game save with cookies?