These Castlevania ROM hacks have complete changes of graphics and major changes of levels.
CV Winter Hack: http://cid-ea81e0060698f530.office.live.com/self.aspx/.Public/Castlevania%20Winter.ips
CV Scenery Hacks: http://plunder.com/7f6d74ffb0
CV Dark Hack 2 (Exciting Dark Challenge): http://plunder.com/a30866cf24
CV3 Scenery Hacks (v3.01): http://plunder.com/a561acd5efhttp://plunder.com/a561acd5ef