I'm completely underwhelmed by...

Meaning

I'm very disappointed by...

Examples

• John: I saw the new movie everyone's talking about.
• Alice: Oh really? <b>I'm completely underwhelmed by</b> the hype; it was quite disappointing.
• John: I thought the special effects were good.
• Alice: Maybe, but the plot was weak. Overall, <b>I'm completely underwhelmed by</b> the whole experience.