Yes, the blockade is there, but once you have the Key gun, you can get through it (if the player is curious enough) and move on past all the enemies to 2 places (if you go in and fall down without the wings, you can't get back to the entrance).
If I'm lucky, I might find the infinite wing flaps power up, but right now, I'm about stumped as to where to find the remaining lore, and Teal (if he can be found...) :s (including the remaining gun upgrade locations; I've only found 4 so far).
Yes, you did mention this on the GameJolt website, but you did mention (on this game's Itch.io page) that 95% of the intended content has already been put into the game, so we can work with that.
I got all the lore from the Canals, after some wall checking with the trusty Chain Core (& some experimenting); there was a fake floor in the tower, but that went nowhere ;)
Goodness, all these riddles will give me a headache XD