Overall: I like the concept, but the game is near impossible. Healing costs 50, but the most I could ever get was around 3 points. The idea of removing the combo when you buy things is cool, and it adds a nice risk/reward mechanic, but I was never able to come anywhere close to buying anything, so I wasn't able to make such a risk. I also think it's awkward how the game just closes when you lose instead of taking you to a "you lose screen" of some sort.
Fun: This ties in with how impossible the game is. If nobody can get anywhere in the game, how could anyone have fun? The controls felt a bit awkward, I would've preferred a combo of WASD and holding down multiple buttons for the diagonals. I've never played a game with a QWEADZXC button scheme, and with the incredible difficulty, I had no time to get the hang of the controls.
Innovation: As stated, the risk/reward for losing the combo on buying something is pretty cool! The rest of the gameplay is pretty standard survival game. Another game from this jam that this reminds me of is "Nobody Grooves like Cadenska Voldmirovna". Its another survival game with an unmoving main character. If you haven't checked that game out already, it's a good example of making the game manageable. Your attacks are at a reasonable pace that keeps up with the enemies, and there are only 4 lanes of enemies instead of 8. Maybe you could start with 4 lanes, and then after say, wave 5, add in the extras?
Theme: If I could survive long enough, the theme would be much more applicable. Again, the combos allowing you to gain points for the shop are critical to the gameplay loop, and so the theme fits. But if nobody can manage the game before their first purchase, the theme is never encountered.
Graphics: The game is readable. Everything looks like what it should. I wish there was a background instead of the default Unity 2D blue, but I think the difficulty is a bigger concern than the artwork.
Audio: Not applicable.
Humor: Not applicable.
Final Thoughts: This game gives off the "My first game" energy, and taking a look at your Itch.io page, this is your second game jam (and your first was just before this one!) First off, congrats on submitting a game! It's incredibly daunting for your first game jams, but once you've done it a few times you get the hang of it. I know there aren't too many comments on this game (or your previous one for that matter), but you should definitely listen to the feedback we're providing. We all had to start somewhere, and rest assured, my first jam games were sloppy compared to my recent work. My first game was also an impossibly difficult survival game with a non-moving main character, and one of the pieces of advice that took me the longest to grasp was "It's not about beating the player". I kept making hard games, and nobody could get anywhere in them, and so my games scored poorly. Definitely consider the player's experience, because everybody loves to win, and not everybody want to put in the time to get good.