Sonic & Ashuro [patched] -

It sounds like you're asking for a (or a fan-thesis) that bridges the worlds of Sonic the Hedgehog (fast, momentum-based platforming) and Shadow of the Colossus (slow, melancholic boss battles). I assume "Ashuro" is a creative blend of Shadow and perhaps Agro (the horse) or a misspelling of Asura (Asura's Wrath).