This is just like that one time I spent 20 minutes until dawn with that vampire survivor!
Jokes aside, this game is pretty good, I'm just a bit worried it'll get lost in the already saturated horde rogue-like genre. I see what you've done to try to make yours stand out, and I think you could go one step further with something like an overworld map that players traverse through with individual levels that progressively get harder and sometimes have different objectives, like surviving for a certain amount of time, killing a number of enemies, causing a specified total amount of damage, etc. The overworld also could give you the opportunity to try out different location themes and levels with interesting obstacles and layouts unique to that level.
I've given similar advice to another game like yours called SoulGerm, where I described the idea of a Capture The Flag objective, where you have enemies protecting a base that you need to clear your way into, grab the flag, and take it back to your home base. This could work out since your map doesn't loop and the character is concealed within a box. The CTF game mode isn't anything revolutionary in games, but I've personally never seen it (nor any other similar game mode) implemented into a game like yours, so it could prove to be interesting.
The decision to implement changes like these are completely up to you, these are what I'd personally do if I was making a game like yours, you can take it in any direction you'd like, I'd just make sure to find a direction you like and stick with it. Competition is tough, so do what you can to stand out in the crowd!