Last night I finished watching the final part of the CW’s DC Universe crossover event. I give the production team kudos for trying something so ambitious. The mainstream reviews fell all over themselves to praise the four-parter and the ratings were sky high so this can be seen a legitimate commercial success.It also means this will happen again and again.I just wish it were more of a creative success. To me, the story really existed only in Flash and Legends of Tomorrow which robbed the story of nearly two hours of room to make this really work.Since the opening chapter was on Supergirl, we knew something would need be done to get her from her Earth-38 to Earth-1 where everyone else was endangered. Yet, the story was all about an alien-killing virus that humans retrofitted into something inert. To me, this was setting up using the virus in some form against the Dominators. Or needing Barry’s expertise to do something with the virus. Instead, neither happened.Similarly, we know Obsidian survived the JSA’s disbanding at the end of World War II so should have still been operating in 1951 when the Dominators first came to Earth. Vixen never even wonders where he is. And were there any heroes active at that time? No clue. But the Dominators, drawn to Earth by powered beings like Obsidian and Vixen, come rampaging and killing, but what was their goal? Rather than targeting the nascent metahuman threat, they seemed to be merely killing humans willy-nilly.Agent Smith (how unoriginal) somehow negotiates a truce which remains in force for 65 years until Flashpoint – but we never learn how the Dominators were aware their timeline had changed. But they’re pissed so come back and once more try to lay waste to Earth rather than start by eradicating the growing metahuman threat. It would have made more sense for the explosion that gave Barry his speed to be the catalyst and it just took this long for them to get here.The timing of the sweeps event was also unfortunate in that it coincided with Arrow’s 100th episode. So, rather than a crucial chapter setting up the final act, we get a wonderful Arrow anniversary episode that was really a great story, but a lousy third chapter.The Dominators as a race were woefully underdeveloped thanks to the two episodes available and getting their butts kicked resolved nothing. If anything, they fled and will probably return with the rest of the alien races that the Invasion! comic book event featured but aren’t seen here.To my mind, there were too many wasted opportunities marring a great idea. That said, there were delicious moments throughout starting with Heat Wave. Mick’s comments (“saved by geeks”) and attitude are delightfully droll and he had surprising chemistry with Supergirl. The entire Cisco arc as he comes to realize that bad things happen even with the best of intentions was a nice cap to what had been brewing over at Flash. Cisco and Felicity were wonderful stand-ins for the loyal viewers. Martin Stein’s newfound daughter (poised to be a recurring player now) is a nice wrinkle to Legends. The growing depth of relationships between the casts and teams is nice to watch and it was fitting the final scene was between Oliver and Barry.The Dominators of Earth-38 are expected as is a musical Flash/Supergirl event in the spring, but this really is just the tip of the iceberg with more crossovers expected. I just hope the creators take the lessons learned here and make the next ones even stronger.