That's a good question. I do know that FastGraph can interface with DirectDraw, which does have hardware acceleration, so short answer, yes it does have hardware acceleration. It can also use its own native graphics library (which has been optimized right down to the Assembler level for the past 10-15 years), but I can't say whether the native library has any hardware acceleration. It's been years since I've toyed with that library, even though I still recommend it to others.
But, if you're asking whether the library is "game worthy", then I can definitely say that it is. FastGraph was create by a 'Ma and Pa' organization of sort. Pa (Ted Gruber) writes the library entirely in Assember, and Ma (Diane Gruber) uses the library to write marketable games. They've even managed to write the library's interface so that it can be used with all sorts of different programming languages (i.e. VB, Delphi, C/C++, etc...). It would definitely be worth your time to download the demo version (if they still do that), and just go through some of the tutorials that Diane Gruber wrote out, just to get a feel for the library.
edit: Oh yeah, and I should point out that they also have a 3D add on to the library for making 3D games. I believe they call it FRED (can't remember what the acronym stands for). If you're interested in looking at another website run by Diane Gruber, then you can go to
http://www.makegames.com