Personally, I thought this series was really good.
The voice acting is excellent. There are some actors who've played the characters before, like Roger Craig Smith's Captain America and Fred Tatasciore's Hulk. But you also get newcomers, like Patrick Seitz (Notable as Dio from JoJo's Bizarre Adventure) as Thor.
The story is also well written. We follow three young children who were genetically modified by Hydra, growing up thinking they were the "Good guys" and the Avengers were evil, before learning they were wrong and lied to all along. It's a well set-up story, with an enjoyable cast of original characters who work well with Marvel Comics characters.
Overall, I like the characters a lot too. It used them all to their full potential, even giving some love to lesser-known or cared about characters at the time, like Hawkeye and Kamala Khan. It also gives enjoyable stories with characters we do know and love, like Captain America's solo search for traces leading to the Winter Soldier in Russia.
I'd say if you can, give this series a watch! It's just a fun series!
