Our game allocated a LOT of memory and that caused it to reach the 2GB limit of browsers. I guess spawning hundreds of mobs, xp point drops, audio objects etc requires some finesse.
It has now been fixed and the new version should be available.
I think the biggest issue ended up being Texture2Ds. We had "SRP batcher" setting turned on for the SpriteRenderer. For some reason the SRP batcher doesn't properly batch the draw calls and the memory was full of Textures. Our sound effects also had lots of silence at the end so they would end up "playing" too long. The sounds would take up more of the memory and they would stack up more being longer than intended.
How did you limit the memory consumption?