Nice twist on the Vampire Survivor-genre. And I love the MagicTek-style visuals from FF6.
Simple but very effective. Nice upgrade paths and weapon have enough variety.
This may sound counter-intuitive, but one thing that would greatly improve the idea is to remove the mini-map. You're too dependent on the small map and you specifically choose this opposite 3rd person view. Maybe replace it with 270 degrees wide rear-mirror. Or have the map/mirror as "weapon" with power up, so you choose visibility over damage.