These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
YMMV: Kamen Rider Kuuga
Awesome Music: NO FEAR, NO PAIN, [...] CHOU HENSHIN, KAMEN RIDER KUUUUUUUUGAAAAAAA!
The music that accompanies the TryGouram's debut, too.
Hilarious in Hindsight: It's stated in the finale that the Gouram was intended to disintegrate if Kuuga somehow grew too powerful, yet it doesn't happen even after he gains Ultimate Form. Fast forward to Kamen Rider Decade, where he certainly qualifies after gaining an additional Rising Ultimate Form...
It was hilarious even before that when Decade turned Kuuga himself into a Gouram, but was further compounded in the Final Chapter movie by Kuuga having the ability to become Ultimate Gouram form at will.
Ho Yay: "...Why am I on your shoulder? This is the blunder of my life..."
The so-called "curse of Kuuga" which, for the longest time (until 2010, when it was apparently broken after ten years), seemed to cause any fan translation projects to come to a sudden halt after about ten episodes.
Nightmare Fuel: N-Daguba-Zeba's debut in his perfect form, which is at the beginning of one of the last episodes where he has Kuuga on the ropes, belt damaged and beaten to the point that Godai can only watch as he starts setting people near by on fire in the rain. All of this is disjointed shown to the audience as Godai would have seen it with his own eyes.
Purity Sue: Yuusuke Godai. He is always happy, has no flaws or weaknesses (being overly willing to sacrifice himself to protect others does not count as a flaw - Tell that to Shirou), and everyone around him not only instantly loved him, but was also infected by his happiness.
In a way, this is more or less required. Kuuga's Ultimate form has the potental to turn the user evil if the user does not have a clear mind, thus starting the whole thing over again. This is the main reason why in Decade Yusake was in Black eyed Rising Ultimate, since unlike Godai, he had a lot of doubts as the series went on, but once he got over them, he was able to control it.
Special Effects Failure: They really should have stuck to practical effects for the monster explosions. They look like something out of a PS1 game.