Compared are the English Version by Cinema Club/Buena Vista (BBFC 15), which is equal to the US R-Rated Version, and the German Version by Cine Plus/Planet Media (FSK 18).

The Minion, actually just a watchable B-Actioner, has officially been released in two different versions:

US Version: The more popular US Version doesn't contain the prolog, which shows a short action sequence that explains how the key to hell is being brought to America by the templers, but the German Version does.
Instead the US Version contains
- some scene and plot extensions, some of them about templers and the key
- two slightly extended action scenes
- another soundtrack with more rock songs and some pop/synthesizer elements.
Furthermore Minion's aura is more sinister in this version, e.g. some offscreen screams are missing in the German Version.
Besides UK, this version is also available in France.
German Version: The German Version begins with the before mentionend back story (including explainations via voice over) which is completely missing in the US Version. On the other hand several plot scenes / extensions are missing plus two short action sequences in the first half. Due to the missing sound effects, the Minion seems to be more human in the German Version. The main difference is the soundtrack: most of the time some ancient orchestral music with bells etc. is being used.
The source of this version is unknown, but it's supposed to be released version in Hong Kong as well.

Labeling one of the versions as the better one is quite a long shot beause the movie is only ok, no more, no less (in either version). Moreover the ideal version would be a mixture of both:
The missing prolog in the US Version is, with regard to the scene extensions, acceptable and the Minion's "demonizing" via the replaced soundtrack is also a positive aspect. Speeking about the soundtrack: here we have the other side of the coin in the US Version. The music itself is way too modern and way too frantic.
In the German Version it's the other way around, the ancient music suits perfectly well but that's the only advantage of this version. Some scenes are really weird plus the Minion seems to be less sinister.
Finally, one has to decide on his own which version is prefered. It would also be interesting to know if there was a version which contains all scenes from the US Version and the prolog from the German Version (but it's very likely this version contained the US soundtrack if it really existed).

The running times refer to the cut version.
The remaining difference is due to the missing scenes in the US Version and the rounding of the running time to a complete or half second.
Running time BBFC 15 Tape: 1:31:50 min (1:27:46 min credits excluded)
Running time FSK 18 DVD: 1:27:21 min (1:23:17 min credits excluded)

Cut scenes: 1 = 5 min 38 sec

Prolog:

0:00
As already mentioned, the complete prolog is missing in the US Version:
A man with a lot of baggage crosses the desert. A text explains to the audience that this happens on 12-22-999 A.D. (which means almost at the end of the first millenium) in the Holy Land. The man recognizes foot prints and follows them across a dune. There he discovers a killing field with several dead knights while two survivers are trying to escape. In the meantime a voice over which says nobody had had any doubts about the fact that, at that particluar time, the world was ruled by angels and demons and that both of them were around the humans any time. Then the narrator says the other order members were from all possible parts of the kingdom and there were Franks, Goths, Celts and Danish, swordmen and bowmen, soldiers and masters among them. He also explains some of them were from close Constanstinople and others from the Scottish Highlands.

The black-dressed man checks the bodies and their stuff to find out if he needs sth. while the injured knights are escaping.
Finally he finds a body with a golden necklace. Happy about that, he wants to grab it but the dead man, apparently possessed by Minion, wakes up and grabs him offscreen.
In the meanwhile the voice over continues. The narrator says everybody served the same master who's "being enthroned in heaven" and everybody fought the devil who lead the human into temptation and tainted the earth. The narrator continues they were good knights who had sworn to defend the Christianity with their lifes. He adds Satan never should be able to free himself and destroy the kingdom of light because they, the knights, guarded the key to his cell. He also mentions Satan planted his semen at the end of the first millenium and Minion, his flunky, showed his treacherous mug. Lethal and unstoppable, he took helpless souls just one after another without having mercy while he was seeking for the key. He adds he knew only one goal: to free his master, the Antichrist.

Possessed by Minion, the black-dressed man follows the two battered knights (several shots of both). When they notice they are too slow to escape, one of them puts his sword in the sand and passes the bag with the key in it to the other one. He says his time had come and that's why he had given him the key. He also says they had guarded the key for 1000 years and tells him to go the coast of Yafo, then he should sail westwards until he reached the end of the world asap.
Minion comes closer while the knight puts on a glove with thorns. He says they had to hide it for the next 1000 years, the other knight agrees. The knight with the key starts running, but then he stops to look back while the other one is preparing to fight Minion.

While is the knight is fighting Minion (not badly choreographed btw), the other knight with the key finally starts running away without looking back. Both is shown rotationally. After the knight and Minion had to take some hits (but Minion was hit by the sword pretty badly: he was hit at his calf and his belly), the knight finally makes it and stabs Minion with his sword.

Minion pushes the knight away, then he pulls the sword (he was stabbed with) out of his body. The knight keeps on running. While a sandstorm is approaching Minion kills the knight on the ground with the sword. The knight with the key, who's far away by now, still attempts to make it through the sandstorm. Minion screams really loud, then he leaves as well. The black image, which is shown afterwards, is also extended. Then the credits start.

338 sec