It sucks. Period.
1. The movement speed is slow and not upgradeable. How can you expect this speed in a vertical shooter?
2. The hit box is too large. Combining this point and point 1 above, it's extremely disappointing.
3. High quality isn't high quality.
4. Selene/Elena confusion. It is a clear sign that the game doesn't get good polish.
5. It lacks a tutorial. It's a deadly sin, you know.
6. Auto-shooting. When my speed is slow, I don't want to waste shots. But now, even when I am in front of the enemy, I still have to wait. Without auto-shooting, I can fire once I get in front of the enemy. (Actually, I think there might be a way to toggle this, but see point 5 above.)
7. It's a bad copy of kupo707's Bullet Heaven. Maybe BH is copying Touhou, but BH does offer something different.
Based on the aforementioned seven deadly sins, I decide that Band of Heroes is just an overrated crap.