Set a specific sprite to entirely transparent?

So I have 50 sprites each one should only be visible when 1 variable is a certain value here is a example

I have 5 sprites that are locked levels but when level 45 is beaten with more than 0 stars the next level sprite is visible and unlocked.

The stars are shown on the beaten level in the level select and so on, if all 50 levels in the level select are beaten with 3 stars the game goes to the story board and then the next world button appears and takes the game to the next level select, once all 10 worlds are beaten the congratulations screen appears, the game is then beaten. So how do I do this? Oh also the game will have a achievements system.

Hi truefalcon, hope this is what you're looking for...

Click on the specific sprite instance that you want to be made transparent.

Look in the Properties bar, under the top (Object type properties) section and note the number against the UID.

Then create an event, pick your sprite and click on "Pick instance with UID", then type in the UID number you noted.

Lastly add your action (check out the Appearance group of actions for your sprite: Set Invisible or Set Opacity)

thanks for the helpful advice...