You may even think Capcom and Konami will sue the creators because of the Megaman-Metroidvania-style gameplay.
The music is very cool and make the game enjoyable. You get tons of upgrades for Ellie but most of them feel like just as keys to new areas. You pet, Chomp, can attain several forms and you must get'em all. The element system is simple but clever. The game always says where you have to go and you must do a lot of backtracks with little deviation from your path to find secrets -- to the point you don't need a walk-through to get 100% completion. The bosses are challenging. The story is almost crap because it's very badly told. The support cast is very undeveloped. Creators of the game seemed to spent all their resources on game play. It's fun to play but you can't play it expecting to see more of the story because it's almost non-existent.
Since metroidvania games are hard to find and this one plays like Mega Man ZX, it's worth a shot.