Can you skip dialogues in Cave Story?

Solution 1:

As far as I can tell, no.

Both Cave Story and Cave Story+ actually attempt to make this more bearable. If you've already sat through a dialog segment and died, the dialog will appear much faster the second time — i.e., box by box instead of scrolling text. These can be skipped through relatively quickly by hammering Z.

Skipping these sequences entirely does not seem to be possible, however.

Solution 2:

The v1.1 update (Aug 3, 2017) to Cave Story+ on Switch added an option to skip cutscenes by holding X.

Holding down X during any dialogue scene will cause the game to run in a fast-forward mode. This will speed up all dialogue and animations with an increased framerate.

Currently the option to skip cutscenes is only available on Cave Story+ for Switch. It is unknown if Nicalis plans to bring this feature to other platforms.

Sources

• Reddit: Cave Story Switch Cutscene "Skip" Added in Latest Patch through Uncapped FPS
• Perfectly Nintendo: Cave Story+: Software updates