I love cards that can "Wow" the recipient. Side step cards are a great because they easy to create but don't skimp on the WOW!. I've made a few center step cards in the past that are similar. They are linked here if you want to see them (friendship, birthday, and cowboy).
The really nice thing about a sidestep card vs. a center step card is you have the ability to create hanging elements that help create that "Wow" impression. This card still fits into a A2 envelope but the fishing pole and sign hang off the card. The steps help create the illusion of an immersible scene.
Stamps: Rubbernecker Stamps
Under the Sea Stamp set