I've been working on a machinima movie version of Shadow of the Colossus. I did some work on it last year, then put it aside. Now I've started shooting again, and am reminded of how difficult some aspects of making a movie like this are.
I'm going to tell you what the hardest part of making this movie is, starting with the other parts that weren't quite as hard.
It wasn't finding an affordable capture device. The WinFast TV USB II Deluxe does a quite adequate job of capturing SD content, at a reasonable price.
It wasn't finding an affordable editing solution. Between VirtualDubMod, AviSynth, and the wealth of filters available for both, capturing, cutting and processing the footage is reasonable if not easy.
It wasn't finding an affordable solution for authoring a high-quality DVD (my target medium). TheFilmMachine allowed me to use encoding bitrates above the limits set by consumer products like those from Sonic or ULead, and between IfoEdit and DVDPatcher I was able to properly mark my video as 16:9 anamorphic widescreen so that all players would handle it properly (something the consumer DVD-authoring products won't do reliably).
It wasn't beating each colossus gracefully and quickly in a single camera shot, a restriction I'm limited to because the music can't be turned off or down.
It wasn't even trying to play the game and manage the camera at the same time, or doing trick camera shots to eliminate the main character from a shot.
No, what is hard is trying to get on the thrice-damned horse! I'd been trying to get the second colossus in a single shot, and made more than twenty attempts before giving up. Sometimes I made Wander tiptoe when he should have run, other times I made mistakes when attacking the colossus, and so on. But the vast majority of the shot-killers were when I tried to get Wander to mount the horse, and instead he ended up leaping through the air next to it. Even with the jump-and-grab trick, I miss the horse more than half the time. It looks ridiculous.
So now I'm going to shoot each colossus in segments, and make sure than any necessary horse-mounting comes at the beginning of a shot. That way, if I muff it, I can immediately retry rather than re-shoot the several minutes that come before it.