This might be a nice modern building, but a waste of money and time if you will get to the exhibitions inside.
Unique Suggestions: In the summer, just sit at the terrace café, nice and peaceful place pointing to the west and there fore, lots of sunshine in the afternoon.
Fun Alternatives: Any of the other exhibitions in any of the other museums in Helsinki
This is just my opinion but I think Kiasma (Museum of Contemporary Art) is a waste of time. I get all the contemporary art I need when seeing this building. I have been there once and that was enough for me. Well, I'm not a big art's friend anyway so forget my opinion if you like the art. You can't miss Kiasma (lucky you ;)) since it's located in the middle of Helsinki.