Ghost Game is painfully mediocre. It started out as really promising, but the writing declined over time. It actually had a solid first half, but fell apart in its second half. Thirdly, as someone who skipped weeks and would binge episodes back-to-back on multiple occasions, the series gets real repetitive, real fast. It's not helped by the fact that Kiyoshiro and Jellymon are the only lead characters who have any sort of chracter development. Hiro, Ruli, and their partners, but especially Hiro, don't really grow as people. That issue is worsened by Hiro being a very reactive, passive protagonist with little agency. Granted, that can be said for the other leads since outside of their focus episodes, Ruli and Kiyo are also fairly passive. Plus, the MOTW formula gets tedious around the second half of the series. For example, the second half introduces a character named Espimon who's useless and his inclusion didn't do much aside from introducing us to a very unfunny running gag that goes on for too long.
Other issues all of the supporting characters and new villains—minus standouts like Quartzmon and GulusGammamon—were robbed of any chance to be more than their starting set of characteristics (if they're even lucky enough to get more than one characteristic), episodes bled together as the show progressed because the MOTW formula got tedious, the series would either abruptly drop or rush interesting plot threads, and the climax of the series kicks in with minimal build-up and is hastily resolved in the final 3 episodes. Even though plot was a secondary focus in Ghost Game, the writers still made the decision to include long-term plot lines and have gone on record about how the show would have said plot lines woven into the episodic adventures, so the "it's supposed to be episodic" card is not an excuse. It's also not an excuse because Gravity Falls, Ben 10, and even glorified toy commercials like The Transformers (1984) would have plot lines that lasted for more than 3 episodes despite most of its episodes being about the Autobots foiling the Decepticons' scheme of the week. Ghost Game also had a tendency to rush whatever plot lines it DID introduce (e.g. the letter in ep. 31, Dracmon unceremoniously dying, Espimon’s subplot, Hokuto being barely relevant, Gulus appearing too little in the series) and climax. The episodic adventures don't fare any better because in the big picture (all 67 episodes), almost all of them (over 75% of them) are "MOTW with body horror powers but in different flavours." The second half is the bigger offender of this because Ghost Game's more enjoyable first half actually has more variety for its MotW scenarios.
I'll end this by saying that Ghost Game did have some good standalone episodes because I enjoyed about 55%-60% of them, but that's on par for an average series. It at least had consistently good visuals and decent animation (for a Toei series, that is), along with the horror-themed direction being a novel one for a Digimon show. Lastly, Kiyoshiro and Jellymon hard carried this show as they were the best-written human/Digimon partnership in this show. At least it's an improvement over the below-average series like Adventure tri., Adventure 02, or Young Hunters.