That's too bad. How disappointing!
That's so disappointing!
Oh no, what a shame!
It's a great shame.
It's a little bit disappointing, isn't it!
It didn't live up to my expectations.
What a pity!
What a letdown!
What a bummer!
That's a nuisance!
I thought you could do better.
I've never been so disappointed in my life.
It wasn't as good as I thought it would be.
