There are a significant number of mecha OVAs produced in the 80s and 90s. Considering that's also the age of a notable majority of notable mecha tv shows and so on, it can be very difficult for OVAs like this to find a voice and purpose amongst the crowd, but thankfully Gaiarth manages this. It creates a fun post-apocalypse setting, avoiding the typical stories and tropes associated with such settings and instead blends a fantasy-esque story with a sci-fi setting whilst quickly crafting several fun lore elements with monstrous beasts and age-old hardened warrior robots whilst daring hunters ride out on mechanical horses/bikes. It works great for an OVA of this length.

Before going further into Gaiarth I feel obliged to mention one of the huge drawbacks, which is that of the three episodes, only two really excelled in quality. The second episode feels significantly weaker than the other two, the production quality went downhill, the story felt slower and less engaging, and even the action sequences the OVA excels at weren't really there bar one exception. With that noted realise that most positives I mention are far more present in the first and third episodes, whilst most negatives are exacerbated in the second.

Action set-pieces are really where Gaiarth excels. Even the most generic of grunt-slaying sequences is visually engaging, with well-done camera pans and great effects as sci-fi swords cleave robots apart with obligatory explosions and bifurcation galore. Art and animation alike combine to make the action work and it's usually accompanied by some music that ranges from cliché but solid, to pretty effective and great. Such sequences make up a decent chunk of the runtime too, it's fair to consider Gaiarth action-packed.

The story itself isn't as engaging, but it all works just fine. It's a serviceable fantasy-style story of a victim of the antagonists pursuing revenge acquiring allies along the way, not a single element of it is original but it's all executed well especially during the first episode, which has a finale so great it's worth watching just for that. The reasonably original setting helps avoid the played out story feeling tiresome also. It's good fun seeing many cliched fantasy character archetypes take more original sci-fi flavours, like the experienced mentor character and the veteran warrior both being old rusted robots of a previous war.

Gaiarth isn't going to turn any heads that don't already enjoy this kind of cheesy action OVA of the 80s/90s period, but I think it's a worthwhile treat for those that do enjoy such content, with the only two things really holding it back being a weaker second episode and lacklustre characters.