If the gaming distribution software Steam were personified, it'd be a yuppie: a young person with lofty dreams, in some well-tailored suit, ready to embrace both the good and bad parts of capitalism. They'd be all about efficiency and streamlined design. They'd use phrases like, "We have our finger on the pulse," or, "Gamifying the game market." You know what you're getting with Steam, which certainly isn't a bad thing.
On the other hand, if Itch.io were personified, it would be a literal mosh pit full of art punks: scrappy, excited, and rough-around-the-edges. It'd reply to questions about content and curation with a shrug and a "Why not?"
Steam might be great for bigger released, but for trolling around to see what folks are working on at the periphery of gaming, there's no better place to go than itch.io
itch.io was founded as a direct response to the difficulty of getting small games onto Steam. An April 2017 article on PCWorld explains:
[Developer Leaf] Corcoran started working on Itch.io in late 2012 as a response to Valve’s Steam Greenlight program, which used a community voting system to let indie games into the store. He wanted to create something more open, inspired by the online music marketplace Bandcamp. Developers would get to list their games for free and customize their game pages. Shoppers would be able to pay any price above a minimum as a show of appreciation, and the whole marketplace would be decentralized, with no way to browse the entire catalog or comment on any of the games.
In this way, itch's ethos centered around "do what thou wilt" and gave both developers and buyers a vast amount of freedom.
With no barriers to entry, itch has grown into a breeding ground for exploration. Developers can test out new mechanics and ideas without worrying about price points. They can experiment with ideas and game mechanics that deviate wildly from the established norms of gaming. Developers can test and patch their games, honing in on what they're excited to make, with no outside pressure besides their own drive to do better.
Meanwhile, gamers gain access to hundreds of games, many of which are available for free or almost-free. Gamers can also get early access to games that are still in progress (like Overland, which I'm currently devouring). It all feels very relaxed and personal, like you've stumbled into a friendly discussion with a group of highly-educated strangers... and weirdos, natch.
Sure, the download process isn't nearly as elegant as Steam, and the UI of the site can get a bit wonky at times, but who cares when you still get what's most important: access to a wider variety of games than can be found most anywhere else.
Looking for some games to while away the hours? I've created a few small collections of games in my itch account: gentlegamer, including games I will always recommend and games I'm eager to get to.
But, with a whole world of games being added by the day, the thing I recommend most is diving in and seeing what excited you.