Just to clear up some stuff.
The SDL.DLL files is a library for SOUND stuff, not video

(Well, unless I am wrong)
And I don't think updating your drivers will male any difference in that matter.
One of the Kenta Cho games I downloaded also gave me this same error, but I already had the .dll here in my computer, so it wasn't much of trouble.
Torus Trooper is AMAZING. I have only played it for once, and I can't say much of its gameplay, but the FEELING is AMAZING.
Tumiki Fighters is his best game IMO. It's simple, the patterns aren't too much complicated, it's simple fun, the way that I like my shmups to be
Parsec 47 is just another upgrade on his "vertical manic abstrat shmup" game

. It seems to be the best of all them though (With rRootage being the weakest).