Tower Master Query

To get this achievement you need to complete ALL the challengers in the tower, not pay/skip them. Can you pay/skip them if your stuck and come back to complete them without paying/skipping later on tho?

You need to pass them all.
No paying.

You can come back and finish those you skipped for the achievement though.

You can buy/skip. Just won't get the trophy/achievement till you have beaten every single one. You can go back and do ones you skipped and still get it.