If you liked Portal’s gameplay, you will like QUBE’s at least 75% as much. The developer video included with Portal 2 explains their original plan: no portals, no Chell, no GLaDOS. QUBE is that, also with no story. What QUBE does have is about 4 hours of puzzles in an environment that feels a bit like running through Aperture Science.
QUBE stands for Quick Understanding of Block Extrusion. The first puzzles relate to colored blocks that do different things. Later puzzles start rotating rooms, using light and magnets, and letting you decide which color boxes should be.
The puzzles are not enormously difficult. Most of the time, once you understand what the tools in a room do, the solution is intuitively obvious. The more interesting puzzles come at the end of a sector, when you get complex interactions instead of new tools.
It can be glitchy. I had boxes teleport, spring away, and disappear entirely. One point requires precision platforming in the dark. About 90% worked as intended for me, and the rest eventually worked.
There is no story and only hints of a setting. There are no words. If you loved Portal for the humor and tone, this will not do anything for you. It just has puzzles in a 3D environment.