This submission intimidates me so much! XD A really wonderful effort. The controls feel smooth and predictable, the mechanic is exploited in interesting ways, the puzzles are well thought-out, the models look great... it's hard to criticise. But I'm gonna, to try to be helpful.
I feel like the pace of the platforms could use a little tweaking. There's quite a bit of waiting around for platforms to get to the right spot, as the environments are large, so are the paths the platforms traverse. So to keep the player from getting frustrated, I'd either a) bump the base speed a bit, or b) provide a way to reverse direction, which would be quite a fun addition.
Are the balls on the final level a bit buggy? They kept disappearing on me. On reflection, I wonder if they were just phasing through the walls of the safe as I didn't realise you had to hold E in order to keep them aloft. Having this separate key combination was a tiny bit unwieldy. Would it work to use the entanglement gun to transport them? I suppose that might make it difficult to manipulate the other parts of the puzzle. Anyway, it seems perhaps checking to ensure they don't end up somewhere inaccessible, or reset to their original spawn position if dropped might be an option.
I noticed when I activated one of the catapults, there was an edge case where I didn't get flung but just stopped on the very end of the catapult. It only happened once, and I couldn't reproduce it but didn't try too hard!
Oh, also as a data point, your game runs fine under Proton (Arch Linux, i5 13600k, 7900XTX) so that should mean you're SteamDeck compatible!
Can't tell you how much this game impressed me. It has real Portal vibes, which is the highest compliment I can pay.