IMO dreams are another tool to play around with. The tone you go for is as always really important, you can go for the "i know i'm dreaming, what the hell is going on" type of dream where the situation is deliberately out of step with the rest of the game and use as a little window onto the dreamers psychological state or go for an "almost real" sort of dream and use it as a tease for the player and have the dreamer wake before getting too far.
The first option is more interesting to me but is more time consuming and involved and tacking it onto a game even if the game is fine without may not be a great idea, the second option is cheaper in feel but far easier to justify in a game due to the limited nature of the dream.
If dreams are going to be one time events then the first option will work better, with a game that has huge potential for intrigue like the Deluca family does this could be another tool for you to use to get insight on what the MC is feeling, even on a subconscious level , however if as you seem to suggest that you'd prefer repeatable minor events then the teasing almost real and wake up may be the best route.