Contrary to my fears, the third and final installment of Hiccup's attempts to start a peaceful life in harmony and balance with dragons didn't disappoint at all. Although the plot is somewhat cliché, and the grand finale of the entire trilogy is simple and slightly contrived, the movie is no worse than its predecessors. Some elements were borrowed from Thor: Ragnarok (in my opinion, it worked well), there are many references to the first and second parts, decent humor, all the old and familiar characters, and pleasant visuals. I enjoyed it, and I'm glad that the trilogy ended on such a good note, just like it began :)
It's a shame that the movie is a bit short. And yes, love is at the center of the plot. Every creature has its pair, so to speak. I was skeptical about this at first, but... they handled it well.
8.5 out of 10