2D Sprite Shape VS 2D Tilemaps - When to use what?

Mostly it comes down to whether you want to paint your levels using a regular geometric grid and even potentially move your characters strictly using that grid although that part isn't a necessity. You can reuse tiles all over the place allowing a pretty detailed design over large areas without having large textures or simpler repeating textures. Tiles work well with isometric (2.5D) views. However you need to author your art using tiles so that's your design decision.

SpriteShapes can give you more control over simpler Sprites allowing a more "organic feel" to them but whilst they are powerful, they may not be suited to a specific game design because each and every part of it is a unique object you need to tweak.

Very quickly it becomes one of, what does my game design require and what would be most suitable for those requirements, not the other way around.

For any game design, one approach will feel awkward and the other less so, potentially both might and you need to use another approach. Personally,

 

"Better". Maybe better for your project. You seem to be looking for absolute rules before you even know your design. It might be "better" for your design in terms of it being easier, more flexible to achieve your goals but it doesn't make it absolutely "better". It also might be more restrictive.

Is wallpaper better than paint? Same thing, what are your design goals.

I'm not trying to dodge a question here though. It simply comes down to understanding what the pros/cons of each are by using them and then decide, in the face of your design, which technology best suits.

 

Hey @GazingUp, I thought that's a great question. I just wanted to chime in here.

Did you know that we have a relatively new-ish downloaded 2D demo called the Dragon Crashers which is available for free in the Asset Store. This demo uses Tilemaps for the Grounds and Walls and Sprite Shapes for the more organic elements such as the rail tracks similar to @MelvMay's point.



Also for pixel art games which requires strict pixel fidelity of 8/16/32 bit like Stardew Valley or Terraria, Tilemaps may sometimes be a better choice (over Sprite Shapes).

 

Yes, you got it! Feel free to play or experiement with either of them as they are both really powerful and extensible tools. There'll also be times where we may need to deviate from these "guidelines" depending on what the outcomes are and that's completely okay too. So long it achieves what you want.