I don't think we have a formal word for this:/
Do you have separate formal/informal words in English?
Разбуди меня - "Wake me up"
Вставай - 'get up'. Commonly used when you are waking someone up. But is a bit different form 'wake up'.
Просыпайся - wake up. Also commonly used. Possibly the least insisting option.
It is imperfective, just like 'вставай'.
There is a certain difference in the way perfective and imperfective are used in imperative. Imperfective is more like an _invitation_. Perfective is direct. It can be a request... an order... a practical instruction or advice etc. When you are preparing to your trip to Russia and I recommend you to take your guitar with you, I use perfective. Because it is advice or a request. When we are travelling together I say "take the guitar and let's go", i use imperfective (unless I'm _asking_ you to carry it, or instructing you or...). So it is not that imperfective is more 'polite'. It is less direct.
Проснись - wake up. If 'просыпайся' invites to start the process, to _do_ something, then 'проснись' means the result: get awake.
This is eactly how it is different - you think of the result, about change in state. Not about what the person should be doing.:)
So it is more insisting may be. Not necessary in a bad way. What if it is said with a playful tone/in a playful context after all? Or what if waking up is in person's interests? Also it may imply urgency as it means the immediate result.