I discovered the songs of the 1st semi final on Tuesday, so I'll give my opinion on the Ukrainian entry.
When I read that the song was called "Tick Tock", I was expecting something cheap and silly. Thankfully not, so far I've listened to the song once and I don't really remember the melody and the structure of it. Some parts of it are interesting but I think it lacks something to be catchy. However, I was pleased with the presentation (which was not tacky) : with the guy in the big Wheel and the background. The singer was pretty (that's always a plus), I don't know what she sounds like on the studio version but her voice was not that strong during the live performance. It was ok. I also liked the fact that she had a long dark dress for a change, since with this type of songs, singers tend to wear miniskirts and short dresses. For now I've mixed feelings with this entry, it was not part of my favourites to qualify, but that's ok with the qualification. Of course, the applause were very loud both after the performance and the qualification, as much as Russia was booed.
I think I need to get familiar with this song before saying if I like it or not. Congrats for the qualification Ukraine, see you on Saturday.