izigame.me

I got this game for $5. It took me about 5 hours to beat and that's after completing everything I came across except for two sidequests (one in particular because it was right at the end of the game and I couldn't be bothered). I'd say that the game is worth $10 for the effort put into it and that's pushing it. $30 is a ridiculous asking price.
SHORT VERSION: Very bare bones. Charming and fun to use the moveset but absolutely shallow and no replay value.
LONG VERSION:
The story starts with an interesting post-apocalypse premise and the game peppers lore throughout. I really liked a lot of dialogue bits that gave you insight into the world and some of the characters. However, as soon as I met the mayor of the setting, I knew I was in for disappointment. Instantly, you can predict that for some reason, the mayor character will turn out to be in the wrong and the "bad guys" you're fighting turn out to be the good guys. It was all a big misunderstanding, greed is the real villain, blah blah blah. The game even lies to you by showing the fake bad guys causing "The Gloom" to spread only to go "No, they weren't doing that at all, look, it's a completely different visual now".
The plot being generic and bland is a shame because there are so many questions the story could have focused on, like the Shadows. These sea-people get some focus and explanation but not nearly enough despite how important the main one is. There were a lot more interesting topics the game could have talked about instead of, "The people were blinded by industry and polluted everything". Not to say that a save-the-planet message is bad but there is no nuance in this game about it.

Voice acting, graphics, and music are charming, as is the main character. Sigrid is a sweet and motivated young girl with a good heart. I suppose she doesn't have too many character traits but she's not boring. She speaks often about her past and gives her opinion often about things.
The gameplay is fun but shallow. The movement and controls are fun but the game seldom challenges you in any way. The only time I felt actually challenged (and I don't mean when the game wouldn't lock onto something I needed to) was during the timed races and even then, those only took a couple or so tries. Your health is far too generous and regenerates far too quickly. Combat is a joke, just being there to give you more to interact with against basic, uninspired enemies.
Platforming is fun but not rewarding. You're only going to be looking out for plot items (which are shown on your waypoint and map so not hard to locate), sidequest items (which are painfully easy to locate and only reward you with money), money itself (which has big indicators and moves around for you to see), and journal entries (which are probably the most interesting collectable but most really don't have anything interesting to say). None of these are hard to find and you will not be rewarded for looking around and platforming skillfully to find them.
The game is intensely linear. You're free to explore as you wish but I think I only came across two instances of anything not directly in path of the plot actually having anything for me. You can't progress in a puzzle or platforming area unless you activate the switches the way the game wants, even if you manage to get to where you need to with creative platforming. And the grappling feature is a pain because you can only latch on at specific angles for some annoying platforming.
Money is superficial. It's used for a single shop that allows you to buy cosmetics for Sigrid. You can change her outfit, hat, and hair. The cosmetics are neat and none are particularly expensive. I think that's fine as a shallow way to encourage you to get money but the game could have used these for harmless gameplay upgrades. Running speed, floating speed, jumping height, additional combat moves, helicoptering distance, and grappling distance could all have gotten upgrades without it harming gameplay. The game would have only benefited from these helping even if they let you skip certain platforming sections. It's only going to shave off a few minutes tops.
The game is absolutely not worth 100% completion. Most of the world lore will be learned just doing the main campaign and very little of the interesting stuff appears in the journal entries.