This was fun. I like the variety of character options to choose from, and getting to pick your starting weapon. It would be nice to have a bit of detail on what each stat does, such as what does luck affect? Is there any benefit to one element over the others for the weapons?
I played through once and filled all 6 weapon slots. I then started a new game while typing this and was unable to purchase any weapons from the shop.
The amount of money you get feels overly high for the cost of the items available. This was even more obvious when restarting and keeping the money from my previous play. The first time I bought the one that looked best, then rerolled. After that reroll was no longer an option. It would be nice if there was a warning that it was a one time thing. Perhaps change it so that it costs money to reroll, but is always available, though perhaps limited to once per wave, or increased cost each use. On the topic of money, is there any benefit to collecting money by walking over it, compared to waiting for it to be auto-collected at wave end?
On the shop screen it would also be nice to see details about the items in your inventory, especially what you get by combining items.
The credits text is a bit hard to read.
Overall, good job.