The good news is that Crysis 3 has no problem with 30 FPS, and cutting detail levels down improves frame rates rapidly. The same Radeon 7950 that struggled to maintain 30 FPS at Very High had no trouble pushing 50+ FPS at Medium. Like the original, this game will scale to match the GPU hardware you have on hand -- and it looks great in all of it.
Normally, I talk about other aspects of a game before discussing its graphics and audio, but in this case, those are the two areas where Crysis 3 really astounds. After Crysis 2 was panned for shipping without DX11 support (and shipping a broken version of that several months later), Cevat Yerli, CEO and President of Crytek, swore that would never happen again.
That's High Detail on the left, Very High Detail on the right. The difference, on a Radeon 7950, is about 8 FPS.
Cevat Yerli swore that he and his team would deliver an uncompromisingly amazing product for the PC. And they did. Everyone who worked in the artistic departments, from character animations to texturing, deserves an award. So does the head composer.
The people who wrote the game's plot, on the other hand, don't.