I received this as a gift on Dec 5, 2015.
The flicker option looks great. However, it drained the batteries in less than one month's time.
The color changing is fun to watch. It has a soothing, hypnotic quality. As the batteries die, fewer colors appear. Red is the last to go. The batteries finally died on March 18, 2016. A total of 104 days.
It doesn't get hot. They seem safe to use. I like it and would buy more.