What sort of magnification and lighting are you using? With good lighting and 10x magnification (I use one of those 10x mag thingies with the handle and LED lights built in, soz I don’t know the name) you should be able to easily tell if you have a bridge between pins.
Also, I found that 3mm solder wick works great at removing excess solder. And, this might be obvious and you already know, but adding more solder and then removing with solder wick is a good way to remove those tiny and stubborn bridges that won’t come away with solder alone. The key to solder wick is to place the wick, apply heat and wait for a puff of smoke before dragging it away IC. Surface tension should take care of the rest. Oh, and flux. I used the type that requires cleaning, like Marqs recommends in his guide. I used way to much on my first board cos that was what various YouTubers did, but it turns out that using just enough to smear a thin layer over the PCB pads gave a much better result.
But, maybe your problem is something else. Given you’ve already been pretty diligent in checking the ICs for bridges….
How is your equipment in general? I spent more than the cost of the DIY kit itself to make sure I had decent enough soldering station, lighting, magnification, flux, 0.5mm solder wire, etc. Figured that I could use it on other projects in future and that I wasn’t just going way OTT with this retro gaming hobing obsession thing 🙂 again… 😀