First off, Kamen Rider Geats is a series filled with interesting concepts.
While it does try so many new things, such as "Reality Rider Show" and "Battle Royal Game" types of settings, the core of being "Kamen Rider" is clearly intact and present in the story. The story, starting with many "grand" happinesses that people desire, slowly turning into breaking from the DGP rules, taking control of their lives, and eventually turning into small yet rewarding happiness, is great.
The main characters are likeable: Ace's manipulative yet caring personality filled with sorrow from parting ways with his family and the torment of living for 2,000+ years just to meet the one he love, Keiwa's wish for world peace that can be shakable but not destroyed, Neon's desire for "love" that resonates with her family more than a typical "love" thing, and Michinaga's ruthless desire that's driven by tragedy.
Their growth is pretty solid as well, and it's present in subtle and natural ways that's don't just flip their entire personality around.
The other characters are pretty interesting as well; from the many viewpoints about "happiness" from other contestants to the satirical characteristics of the DGP management to criticize the entertainment industry (mainly Japanese), from the "Vision" of each producer, to how the Supporters of each Rider feel about their favorite contestant.
The action and fight scenes are pretty great, especially when they use their environments and gimmicks in the fights, creating creative fight scenes and stunts as a result.
Now for the cons:
-There are a handful of plots that've been mentioned but not explored enough.
-Keiwa's arc towards the end of the series has quite bad pacing, and sometimes makes the audience feel like it's dragging it out too much Keiwa's characters look dumb.
-Tsumuri's arc and characters can be so much more after the goddess incident.
-Suel, the final villain, while being a nice satire to the "control freak" and deceiver type of producer, his personality and interactions as a character towards the main character are pretty bland, especially when compared to other game masters and producers such as Niram, Girori, and Chirami.
Overall, it's a great series with noticeable flaws, but the flaws are clearly bested by the other great parts of the series.
Truly a highlight, highly recommended.