Thanks! I'm glad you enjoyed the art and upgrade system!
The customization screen arrows aren't actually real buttons, it's just one button that advances to the next option. Mouse support there is more of a bonus, as we had to target keyboard/controller only for the sake of time.
The projectiles is sorta intentional/known - the player's hitbox is at their feet, while the projectiles spawn from their center. This is so that they can have extra space to move around and can appear "above" the wall, but does lead to some weird interactions with projectiles... Maybe we could have had the edge of the walls not have collision so the projectiles work in this case? (and they would be easier to use in hallways too!)