What is required to "go up a level"?

"Go up a level" strictly means adding enough Flowers to your island to add one to your level, as shown in the top right corner next to your profile picture. How many more Flowers you need is written to the left of your profile picture. Just starting a new scene does not necessarily count if your level is ahead of your scenes opened.

My game automatically turns off arbitrarily taking away lightening bolts I’ve used, coins, etc.

I have plenty of space on my iPad, turned game on and off, internet connection checked, upgraded game anything I can think of. Could my game be compromised and should Wooga look into it? Also, does anyone else have this problem, it’s quite annoying during competitions because I loose my progress and need to start over!

You also have to accumulate enough ‘flowers’ to unlock the next level. The easiest way to get flowers is to buy items for the island.