My feedback for Into the Depths:
What your game does well:
Your game incorporates the theme into its story and its gameplay. The player has to control both characters in order to survive until the rescue team arrives.
The art is simple and readable. It's easy to tell which room is which based on the manual's names for each.
Controls are responsive and simple. Climbing ladders is instant and helps save time when the inside character needs to extinguish a fire.
What your game doesn't do well:
The manual is difficult to read, and it's harsh on the eyes. When you have a pixelated font you have to be methodical about how large it is and how much of it you're giving to the player at one time.
The gameplay got stale after a few minutes. It seemed like all there was to do was put out fires. Eventually I stopped needing to switch to the outside character entirely
No Audio.
Areas of Opportunity:
I saw there was more than just the room names with switches in the manual. I imagine you had more planned for the inside character to do.
This game could be phase-based. That is, in phase 1 the inside character only puts out fires, and in phase 2 the outside character takes charge and guides the inside character to the transmitter and how to operate it.
I hope this feedback helps!