A new event started in IOU. It's almost like a little tiny tower defense mode. It's quite strange and I've been slowly plugging my way through it. The rewards are pretty amazing so I'd like to make it as far as I can before the event ends.
The basic idea is, you buy and upgrade a group of units then face progressively harder waves to unlock prizes. Pretty simple but takes a bit more time than the previous event. My goal with this game was to have fun on a minimal time investment so the event is a bit against my goal but I've still been enjoying it but I can see getting bored of it over the next few days. Hopefully that doesn't happen and I can keep cruising on with IOU.