Tip: Layer 3 backgrounds and tides disappear when you hit a message box, so plan your level around that. For example, you can add a sublevel without layer 3 at the start/midpoint, and include your message there.
Replaced the puzzle tag with traditional, since there's nothing puzzle-ly about this one.
What's done here works in concept, but needs some serious assistance in execution. The main flaws about this hack are that you need to complete it all in one go because there are no checkpoints and the single level carries on for a long, long, long time. The best way to approach this without having to change too much would be to add an invisible checkpoint at the start of each room and to give the player truly infinite lives. Doing those should alleviate the tension that player will have drastically.