This crash always happens after playing for around an hour+ (Only playing co-op) and a little box appears that says Fatal Memory Error or something. I'm pretty sure it's not my computer running out of ram as it has 16GB and Nuclear Throne gets to around 1gb Ram usage. Does anyone get this problem as well as it's extremely frustrating getting to l2 + and crashing.

Might be a system-specific issue - you can find multiple 2+ hour long VODs of NTT.

Nuclear Throne is a 32-bit application so it cannot use more than 2GB RAM at once (which is the point where it should be crashing).

Hard to recommend any particular solutions, to be honest. I know that the base game had a tendency to crash at 0-1 boss intro, but I seem to have fixed that without figuring out the source of problem. Could be that something is only amplified enough in coop mode, but it's hard to tell if most people don't have the issue. If it crashes at some particular points (e.g. boss intros), that could provide some clues.

So far it's crashed loading into 7-3, after hitting the nuclear throne skeleton and right after going into the portal after defeating throne 1. This all happened in loop by the way. Of course it doesn't always happen, it just seems to happen after playing for around 1 hour +

I found out that Nuclear Throne was running on integrated graphics, I've changed it to run on NVIDIA GPU now. I'll get back to you if it keeps crashing or not.

I haven't crashed a single time since switching from integrated graphics to NVIDIA. It seems that was the problem