This is one of the better ones of SyFy Channel's own production featuring the hydra, a creature taken from Greek mythology (but although it usually has nine heads it starts with three of them here). Compared to other productions of that sort it is remarkable that most of the special effects scenes do not look all that cheesy and that it can get quite brutal. Starting with the pretitle scene quite a few of victims are torn into pieces and, although those scenes can be recognized as CGI fairly easily, most of these shots are quite well done. But, of course, in terms of story, acting, the score and so on one shouldn't expect too much.

Like several other movies of this category "Hydra" has been released as a special Unrated version. The extensions compared to the normal version that is also available on DVD, however, aren't really orth mentioning. There are only three somewhat unnecessary new story scenes.

Running time designations refer to the R-Rated version.
The rest of the running time difference is due to the different speeds of NTSC and PAL (the R-Rated version has been taken from the German FSK 16 DVD which contains the identical movie) and the rounding to whole or half seconds.
3 Cut scenes = 3 min 44 sec

0:00
The UNrated version starts with the First Look logo (not taken into account for cut stats).
15 sec

6:48
There are different title overlays.
No difference in time

FSK 16:	Unrated:

33:29
Captain Sweet watches the Tracing Monitor, his technician Daniel comes into the room and says that everything would be in order except the fact that the prisoners that have been taken to the island weren't moving at all. Sweet says that they were just afraid and that he should give them more time. Daniel goes again, the Captain looks at his monitor.
54 sec

57:33
Tim & Gwen are having a small break. Gwen says that they probably deserved all this because they all have committed crimes. She then tells Tim that she killed her husband because he hit her regularly and that she wasn't accounted legally sane in court and possibly really was crazy.
She then asks Tim what their chances were. He answers that he doesn'T know but thinks that they do stand a chance.Gwen remarks that she was content with that. A sound from the woods startles then and they move on.
104,5 sec

1:17:57
Some more shots of the island, then Tim & Gwen meet Jenkins, who is still tied to a tree. He begs them to set him free and says that he would give them money, but they leave him there. The vulcano gets active again and the island is shaking.
65,5 sec