Dungeonmans has an interesting strategy to teach players to move diagonally early in the game, without requiring a wordy tutorial.
The first level has caves with loot inside. Some caves are straightforward, allowing players to reach loot without needing to perform a diagonal step.
### #o# #.#
But other caves are different, requiring diagonal movement to get the loot.
### #o# ##.
Presenting the diagonal movement mechanic this way is easy and low risk. If you don’t pick it up, it’s ok. You won’t die, you just miss out on some loot.
It’s also low disturbance. There’s no dialog popping up saying, “Hey! Listen!” The players will either get a kick out of figuring out how to get that pesky loot or simply move on and play more of the game.
It’s a win-win situation.