Hi! I'm the guy who always likes giving feedback even if people don't want it, LOL!
About the 1 BIT rule: By post-processing I think the rules meant that you can achieve black and white with post-processing (so if your object is in color you can apply some shader or PP so the final product is black and white), not the other way around like you did (using PP to draw color and circumvent the rules that we are all subject to in this jam). But I'll give you a pass on that because you seem to have genuinely misinterpreted the rule.
Or maybe I did? Maybe you can make a full color game on a 1-bit jam but only if you fully use post-processing? which would make no sense, but whatever. So let's leave that aside.
At first I was like "oh no, another platformer prototype starring a square" but as the game progresses it gets more and more elaborate and I could see all the work you put into it. I also played (briefly) your other two games to understand your background, it looks like you're learning Godot or even game development, and I think this is a solid project, you added a story, made a short game from beginning to end, you implemented a lot of stuff (sound, shaders, enemies, mechanics), judging by your previous two games you've learned A LOT and you managed to make a decent game jam game. You should be really proud of yourself.
I'd suggest you keep participating in game jams, ignore the negative feedback, and as you said, keep improving as a game dev, it's the only way, it's ALL practice, be patient, it takes time and many many projects, keep learning and you'll get there.
Yes, the game in its core is a basic platformer starring a square, but I'll give you a decent rating because it shows all the effort you put into the game. Keep it up!!