Well, Colin's first appearance on the show certainly makes an impression, particularly since Charlie O'Connell shines as the character. The minute he appears on screen he fits right into the character, and right though the episode he proves how interestingly naive Colin is going to be throughout the season and what an asset he is going to be to the show.
I won't go into the 'non-Colin' plot of the episode, since it doesn't really appear until after the first 30 minutes, and it's hardly important. Colin makes his first appearance (he is listed as a guest star, not part of the regular cast) when he flies in on a hang glider in the countryside and prompty crashes into a tree, only to be chased by the locals for his wacky and unconventional devices.
Colin doubts Quinn's claims of parallel universes, but when a microdot is discovered in a family heirloom in his house, Colin accepts the truth and agrees to slide with them in order to find his and Quinn's parents.
On the new world, Colin is astounded by cars, television, phones, and even the Yellow Pages. He also discovers the world of women's fashion. The way Colin talks is also very fitting to the part, speaking proper words (no "can't" or "don't," just like Data in Next Generation, but far more human).
Now the nit-picks.
Supposedly this episode takes place right after "World Killer," yet the team wears different clothing and Quinn has some facial hair. Is it really that difficult to put the same costume on a character in two consecutive episodes?
This episode marks the fifth time this season the Universal town/city set is used, though more and more new areas are shown, so it's not so bad.
There is some further stuff mentioned or seen in the episode. In Colin's vision from his parents we learn new info; that humans on Kromagg Prime were captured and enslaved by the Kromaggs, something not mentioned in Quinn's vision in "Genesis".
Maggie again has all the best one liners, mainly concerning Colin's dim-wittedness, and she is also the butt herself of several remarks on Colin's Earth, and Remmy instantly takes a liking to the new Mallory brother. We learn that Colin wasn't found by his real parents since his foster parents died at an early age and he has moved several times since, keeping mementos of his family.
The best 'neat-pick' of the episode has to be the Quinn discovers his parents were able to control sliding more than the viewers were led to believe. They can also allow co-ordinates to lock on to specific areas and things including people with slide signiatures (for example Colin).
That's all that can really be said. I think Colin's pretty damned good and will really make himself important to the show.