I can't add much more than what the other positive reviews have already stated. (Although I do want to call out what Dixie G. said - The goat cheese with beets salad was excellent.)
They have a decent menu and strong selection of drinks. The prices on everything looked more than reasonable.
Overall the vibe at the Bossanova Lounge is great. It's a hip looking place with a lot of people havin' fun drinking and eating.
If you're living in or traveling to the Alton area, check this place out.