Were you disappointed that
1) Jack died and didn't make it off the island and the ending just skipped past their lives off the island
2) where you more disappointed that mysteries went unsolved?
3) Something else
Me, personally, I was disappointed that Jack didn't make it off the island. I was seriously hoping that the sideways reality was real and they could make a difference there so it would affect the island and somehow remember and live happily ever after.