Apathetic. In one word, that's how I would describe my reaction to Trapped in Time. There is nothing ostensibly wrong with the film, but ultimately it just didn't really do much for me. The animation is well done, but the style used is not one I particularly enjoy, with most of the characters appearing malformed to my eyes (even for superheroes). Similarly, voice work and scripting was fine but didn't fit that well with how I hear these characters in my head already. There weren't any "a-ha!" moments here, as with hearing Nathan Fillion's first take on Green Lantern or Matt Ryan's portrayal of Constantine.
The plot is average as well, with a contrived storyline about two heroes-in-training from the future accidentally unleashing a cryogenically frozen Lex Luthor on the past. Both heroes are trope-filled and two dimensional, with a clear moralistic plot arc with very little complexity. Plus, they also happen to be the key to saving the day, even when the likes of Superman and Wonder Woman can't hack it – shock, who saw that one coming!?
To be fair, the introduction of Time Turner as the key villain, goading Lex into a temporal trap and then taking control, was neatly done and lent an element of interest to proceedings. However, the reasoning for his desire to take over Earth is never really mentioned, let alone explained. Having been caged like a mythical genie, I would personally have taken my freedom and ran to some lesser planet with fewer superheroes running around. But maybe that's just me, and I clearly don't think like people in this universe. I mean, I would also not have left world-ending superweapons and imprisoned entities of immense power just casually lying around a museum without any more of a security system than a knee-high rope. It's not like this is the future with immensely advanced technology or anything...