It starts out pretty but empty. Generic light action with lots of energy and not as much characterisation as it could have had. I didn't like it. Things improve later, though, and I actually quite liked the last third of the series.
Our hero is a teenage boy on an SF planet. His name's Sogo, he likes going fast on hoverboards and he's nice. That's the sum total of his characterisation. That's not necessarily a problem, though, because bland anime heroes are ten a penny and there's always the girl(s) to pick up the personality slack. Unfortunately the girl on this occasion is Felia, who's even more underwritten than he is. She has some excuse for not being able to operate on the level of ordinary people, being an SF Mystery Glowing Girl with telekinesis, but for a while I was getting mildly annoyed with how shallowly she was being written.
She starts out child-like. She gets excited about things like food and butterflies. She's always happy. She wears a magical flower pixie dress. In short, she's a Bundle of Cute with the intellect of a pre-teen and the depth of a puddle. Theoretically the ability to lift cars with her mind should make her a bit more interesting, but it doesn't because she hardly gives it any thought. Later she matures a bit and we're told that she's grown emotionally and learned from her friends, but this is informed development rather than something we've observed. The nearest we get is a "What Is This Thing You Call Love?" scene that would have been even more eye-rolling if it hadn't co-starred Kaon (who's actually a good character). At least Sogo is plausible as a human being. Felia never really stops being a Bundle of Cute and it's hard to say that she really demonstrates mental processes, or indeed much intelligence.
She's terribly nice, of course. Sogo's nice. They're both nice.
There's also a Cute Animal Sidekick (a rock snake-caterpillar called Moura), which I disliked. I found it unconvincing. It uses affected speech patterns that I found annoying, while more fundamentally I was wondering what the point was of it being in the show. ("Can turn into a mecha" doesn't count. Eventually we'll discover what its function is, but that's later.) Also it's a stone, but it eats human food. I'm not calling that impossible, but I wanted the show to notice that this was peculiar and at least suggest a possible explanation. Nope.
Even the villains underwhelmed me for a while. In ep.3, our heroes splat with cake a random passer-by who happens to be a mad evil genius paedophile scientist who can control all cameras on the entire planet. Or something. He's a twat and I rolled my eyes when another villain recruited him. Meanwhile Pack has a decent psycho introduction in ep.2, but after that becomes a repetitive brat.
The show does look pretty, though. The planet is light, colourful and interestingly designed. I loved that observatory and Roman's egg-shaped Humpty Dumpty mecha. You've got gorgeous shots like the autumn colours and the waterfall in ep.7, or the lovely costume design for the wedding in ep.6. (They looked a bit Greek.) What's more, the early episodes have lots of light, happy action that's fun to look at and makes the show kinetic and high-energy. My only problem with those action scenes is that it wasn't always clear what was happening. Stuff happens. Magic crystal girls materialise. Some combination of powers (from who?) can make giant robots appear from nowhere.
Unusually for me, I actually liked the mecha. (It helps that they're a relatively minor ingredient.) Even if everything else in the story is a bit handwaved and unclear, at least you know what's happening when you see a piloted giant robot war machine.
Significantly, this was the first original anime of a studio (8-Bit) that had previously only adapted other properties. They did Infinite Stratos (which was a hit) and the Grisaia anime (which I enjoyed). Here I think they worked really hard on making something that would pop off the screen and have lots of action in a roller-coaster Miyazaki way. That they did. They succeeded. Visually, it's a lovely, inventive piece of work. Even the sound design is top-notch. However personally I'd have liked to see more effort go into characterisation and narrative clarity. That said, though, I did watch all of it. It's not that bad. It does look pretty and there are characters I like. The first half of the series would sometimes make my eyelids heavy, but it improved later. (Some people don't like the ending, but personally I thought the show was at last finding some content.)
Kaon I liked. She's Sogo's childhood friend and she has emotions, motivations and dramatic force. She has someone she's trying to avoid (her fiance). She's great. Whenever the show comes alive in eps.1-8, it'll almost certainly be due to a Kaon scene.
Events get weightier in the second half. There's some brutal backstory. People die. What happened to Sogo's mother years ago is horrible. A lovely, gentle fellow turns lone wolf and starts killing everyone who gets in his way. Then the last couple of episodes have some downright cool stuff going on, with big cosmic ideas and no guarantee of a Disney ending. I might, perhaps, have got upset if I'd cared about the characters, but I didn't really and so I thought it was a laugh. It's spectacular. Can't deny that. I actually respect that ending for being a bit more spiky and extreme than you'd have expected from a show that had started out so bland and pleasant.
I don't think it's really focused on storytelling. The characters tend to be underwritten, bland and/or a waste of space. The plot has big ideas and is a lot less fluffy underneath than it looks, but you've got to wade through all that light family-oriented stuff in the first half to get there. If I'd been better disposed towards the cast, I'd have probably found all that charming. It does look good, though. Well designed and animated. My problems above are all subjective and quite possibly just me, so I wouldn't be surprised at all to find someone who loved this show and thought I was talking rubbish. Personally I'd struggle to recommend it, though.