Mellowlink Arity is good enough. He dodges, snipes, and somersaults across the battlefield, and enables this OVA to be a fine, action-filled adventure. It's a boilerplate revenge story in high form, with an art style that faithfully follows the original Votoms - along with carrying the same level of quality. Most episodes are individual scenarios in different locales: jungles, deserts, etc. And all are opportunities for revenge for Mellowlink.
The story is mostly episodic, though the plots of earlier episodes contribute to the multi-episode finale. Unfortunately not a lot of these episodes are memorable, though there are some diamonds in the rough. A big problem with Mellowlink is that the characters are paper-thin: while Votoms has eccentric and comedic characters to contrast with its stone-cold protagonist, Mellowlink's cast is much smaller and everyone seems to carry the same flavor of bland, minus the love interest. While that may seem like a saving grace by mention, it's really not. She's a pretty face with more mercy than the rest of the cast, but disempowered by the plot and kind of boring anyways.
There's still a lot of good here. The character designs are faithful to Votoms, the armored troopers look great, and as a visual package the OVA really pops. I really like the choreography of the action, even if it gets a bit repetitive by episode 8 or so. Seeing Mellowlink outsmart pilots with his AT rifle is great, and as other reviews have pointed out it's solid David vs. Goliath fare.
I'd recommend it, honestly. It's a short action OVA with good action in a gritty world, and it's altogether reliable: when you start an episode of Mellowlink, you won't get any crazy curveballs. It's 24 minutes of solid battles in a gritty world. Although I wouldn't be in a rush to watch it: check out the original Votoms first.