I know the feeling - I accidentally ended up doing 2D sprites, animation and rigid bodies for the first time in mine, so didn't find time to make something playable (or to add a menu, or to add sounds, or ...).
I had a quick go at the updated version and already it looks like you've made some massive improvements. The jump feels a lot better, and everything feels a lot smoother with the longer platforms. I also think the decision to have the player spawn near where they died is much better than going back to the start.
If you're interested in further feedback, I think you need to either slightly increase or decrease the default vertical distance between blocks - as it is, it's possible to get kind of wedged between them. I also found myself falling straight through some blocks; I don't know if that's due to a gap not being drawn properly, or out of a need for interpolation in the collision detection.
I think one of the big dirty secrets behind FTL and Binding of Isaac is how much isn't random. If I remember correctly, all the enemy ships in FTL are hard-coded, or hard-coded with some minor tweaks. Binding of Isaac has a number of room templates that it makes minor changes to. Maybe some sneaky behind-the-scenes authored content with a random layer on top could work well in yours too. Hurray for backseat game development!