Cloudbuilt is almost purely a skill-based game. If you enjoy mastering the tools that were given to your disposal to overcome the ever growing challenges, than this might be the game for you. Developers did a fairly good job designing the levels and even though some parts might look impossible at first, each and every attempt you make will result in improved understanding of the game, in turn getting you closer to your goal, while almost never feeling unfair.
When everything clicks together Cloudbuilt can be a very fun game, however it might not be the case when playing for the first time. Probably the biggest complain one might have with this game are the controls - they are just not intuitive and sometimes even work against you. For example when standing on the ground or free falling, "jump" button will send your character up, while "boost" will send it forward, however when you are wall-running the "jump" button is the one that sends your character forward (away from the wall) while "boost" will make her go up, ascending the wall. Sure the game is designed to make it seem logical, but when you mess up a jump and land on a wall that is right below a ledge you were aiming for, and you have less than second to make a decision, you only can think of one thing: "I want to go UP!" But sliding down a wall the button that makes your character go up (and thus could help you reach the ledge), in this case will instead send your character flying into the oblivion. This counter-intuitive behavior is something that will most often contribute to your deaths.
Speaking of controls, Cloudbuilt supports the controller but it is clearly not designed for it and it might as well support a steering wheel or a dance mat - both will be just as useful as a controller.
Less annoying but still worth considering are some of the game mechanics: limited retries, limited ammo, limited boosting or placement of your own (limited) checkpoints. Not to mention later levels introduce moving enemies, in turn bringing a bit of luck into the game-play. Honestly, on first playthrough Cloudbuilt is more of a puzzle game than anything else - only after you finish it and master the controls, you can start thinking about doing actual speed running... but by that time, there already are no reasons to do so.
All in all Cloudbuilt is not a bad game, it just needs a bit of getting used to.
Or maybe it just needs a sequel.