First of all, I have to say that I've been enjoying Kyoryuger quite a lot up to the finale. However, there were several things in the final episode that ruined the ending for me:
-Daigo & Amy: I have no problem with romance in Super Sentai, and I don't have a problem having this two characters together. But they can't just shoehorn it in the last 2-3 eps and expect us to accept it, especially after having Yayoi being infatuated with Daigo since her introduction but did not seemed to mind in the end when Daigo hooked up with Amy. And does it really matter to the story at all?
-Daigo as One Man Army: Throughout the series, it is clear that Daigo is the central figure of Kyoryuger, and it is particularly jarring when he turned out to be the only one who received the power-up in the team. But to let him go mano-e-mano vs Deboss is ridiculous. The last time I checked, this isn't Kamen Rider, so why can't the team face Deboss together?
-Deus Ex Machina: I know in just about every final episode, the heroes will pull something out of their butt to defeat the enemy, but having the Kyoryuger just sing a melody to weaken both Chaos and Deboss and helped heroes win with ease is bad storytelling. I know they wanted to rush to Epilogue but that doesn't excuse the way they did it.
-Epilogue: I don't understand why we have to suffer through the long Epilogue to find out that Daigo is indeed alive, when we can predict that he'll survive from the beginning. And to have Amy going from a strong, independent young lady to one who was sobbing for her new boyfriend's apparent demise was rather disappointing. It also have no reason to have taken half of the episode to do the reunion, either.
I didn't even mention how they killed off Ucchi then letting him come back via melody. Anyway, it was a badly-handled finale and one that I won't feel like rewatching in the future.