Cube & Star is an exploratory game where you are a cube spreading color across the world. The game was interesting, and it's the type of game that I would like to see more of, but the gameplay leaves something to be desired.
I think it's a problem that most video games primarily feature violent combat, and I want to see more games that are enjoyable and let you do something other than fight your way to victory. I think that, in its essence, Cube & Star is trying to do something engaging. It presents a bleak world that you can make colorful. You can build cities. You can collect things. And if you want to learn more about the design and history of the game, you can read the game developer's postmortem on the game as well, and that article is itself fairly interetsing.
However, there isn't a ton to keep me enrapt in the game. Exploration can be an interesting motivation, but that requires good content that is intrinsically interesting. Guild Wars 2 did a fairly good job with this -- you could go to the top of a mountain, and you were rewarded with a beautiful, scenic view. This is also at the core of games like The Stanley Parable where, in a sense, you're exploring a story (though that game defies categorization to a certain extent). The content in Cube & Star, however, was procedurally generated, and there wasn't very much of it.
Creating something that is yours can be a powerful motivation, as we can see with games like Terraria and Minecraft. In Cube & Star, though, the tools for creation aren't very high fidelity, so it's hard to make art, and there isn't a way to make anything that is useful either.
Overcoming challenges can be a powerful motivation, and that's usually at the core of the enjoyment of difficult or competitive games. I don't think that Cube & Star tries for this one.
Achieving goals can be a powerful motivation. Cube & Star did go for this one. There are collectible items, but the process of collecting them isn't intrinsically engaging because it's too easy, so this is just a grind. There are also qualitative things to do, like making certain buildings or encountering certain creatures, but the game doesn't provide guidance as to how to actually do any of those things, and if I don't know how to aspire for something, that thing can't really bring me back into the game.
All of that is to say that I completely support what Cube & Star was trying to do, but I don't think that it was executed very well.