This is brilliant. And perfect for a lazy Friday afternoon. Similar to Jonathan Blow's Braid, Tyler Glaiel's Closure is a puzzle game presented as a platformer where the emphasis is very much on figuring out what to do rather than taxing your manual dexterity to actually do it.
Without giving too much away, as part of the appeal is deducing its cleverness all on your own, it's all about using light to navigate your way through the environment. You can pick up and place globes of light to reveal - and also conceal - the arrangement of platforms and walls. Give it a go then come back to beg for help when you inevitably get stuck.