A while ago, there were topics made on the freeware action-adventure game "Cavestory" by Daisuke Amaya. Simply put, I loved the game, and I believe that although it was still popular in a way, I do consider it a bit of a sleeper hit so to speak. But since I enjoyed the Metroid/Castlevania style of gameplay that the game offered, i've become interested in finding games that are similar. Are there any similar freeware PC games that a Cavestory fan might enjoy? I'd rather not shell out any money if neccessary, unless the general consensus is that it's worth it.

P.S. I vaguely remember a similar game, but I don't recall the name seeing as how it didn't keep my attention for very long...actually I believe it was more of a NES Castlevania style of gameplay than one that is similar to Cavestory. I believe it had a Spanish name, La Mulan or something. But that was a while ago and I might of had too much going on at once to really care(this initially was the case with Cavestory, but I loved it the second time that I tried it.)