With a mat, a stability ball, and maybe a dumbbell or something that's heavy to hold in one hand straight up overhead, you've got a complete core workout right here. Pause if you need additional rest. Once you're able to do each interval to your satisfaction, use skimble's "additional setup time" feature to add time on to exercises to make this a bit harder.
We love these adjustable dumbbells from Rep Fitness. They take up very little space and are also very durable compared to other adjustable dumbbells on the market.