The notifications fade into the screen (…)
Don’t do that. Making them appear suddenly would catch more attention.
With that said, motion is probably a good idea. You can make the notification slide in the viewport.
Another thing to try is to have a sound effect associated with it. As long as it does not bothers the players too much.
We could argue for other stuff to draw more attention to it, however, we would be into annoying territory.
How exactly do you design your tutorial? Usual wisdom is to stop the player until they perform whatever they are supposed to learn (be it from following instructions or figuring it out by themselves). Then again, over do it with the notifications, and you are in hand holding territory (notifications says do x, then do y, and so on).
For example, if you need to teach how to break objects. Put breakable objects blocking the way. A good pattern is to:
- Provide a safe space for the players to try out the mechanic.
- Place some obstacle that can only be surpassed with the mechanic.
- Give the player more advanced challenges involving the mechanic.
- Give the player challenges that involve using the mechanic in conjunction with others.
Plan ahead how you would do that for every mechanic you introduce. In fact, your tutorial does not need to look like a tutorial. Nor be front loaded. You can spread it out, and teach mechanics as the player unlocks them.
If players are having difficulties with learning the mechanics, consider working on the mechanics to make them more intuitive (see the concept of Affordance). In fact, some hints can be useful. For example have some way to highlight objects with which the player can interact with (perhaps that can be disabled via menu). Which reminds me of assist mode, but that is another tale.