I'm extremely shit at relationships, so this is probably the worst take, but I think the execution was lacking. The focus on lying I think was also a misstep, given that the rationale for the lies was sound. There's more to be said about how they're romantically incompatible: Amber has certain needs that Mark can't provide. It's perfectly reasonable for her to end a relationship that isn't working.

Personally, I felt bitter because of the University scene. Mark was punished for saving his best friends life and not telling his 5-month girlfriend about a secret that could get his mother killed. The sad thing is that Eve was 100% right, he shouldn't tell her, but also, it was selfish to string her along when he knew he couldn't commit. The lies themselves weren't the problem, considering Amber knew Mark's rationale was sound. The bigger problem is that Mark kept lying to himself, failed to live up to the promises he made, and continued to ask for second chances he couldn't make good on. It's a brutal lesson for Mark; not only can he not save the world, but even the attempt means hurting the people he loves and sacrificing relationships. But the dialogue seems stilted towards punishing Mark for interpersonal deceit, which I feel is a really superficial approach, and also, justifiable

The sacrifices, choices, and deceit of superhero work are basically the romantic theme of every spider-man movie. It's not a new message, but the reveal could have been a fun take on the trope.