Battle Fantasia might not be as polished or balanced as many of the big name fighters out there, but it's a lot of fun, and criminally overlooked, especially in retrospect to its overrated cousin BlazBlue.
Although it is similar to Guilty Gear in many respects, it doesn't just copy-paste and then screw with the source code like BlazBlue does. Battle Fantasia's visuals and gameplay tweaks allow it to stand on its own two feet without completely falling over. Characters, although many of them have callbacks to GG characters, are different and endearing. The more fantastical setting really stands out against Arc Systems' standard post-apocalyptic fighters.
Overall, Battle Fantasia really deserves a look for anyone wanting something familiar, yet different.