Programmer for GS here! We appreciate your support. Level Design is the #1 item on our list. Typically, we had just one person going through levels and designing them. Moving forward, we're going to have a sort of 'iterative' process to hopefully avoid issues like these sections (after going back and fixing the current ones!)
And yes, Steam release is the plan!
For tips on those sections with the diamonds, keep in mind that they reset BOTH your jump AND dash