Is there any benefit to breaking the checkpoint orbs other than gems?
I was passing by one of the checkpoint orbs, struck it, and noticed that it was breakable. After I broke it, I got a gem but also found that I couldn't respawn at it. Is there a incremental reward for breaking all the checkpoints in a stage, or is the reward linear, i.e. you get the same gem for each checkpoint with no reward for breaking them all?
Solution 1:
From the developer's site (article on checkpoints):
The color of the flame dictates how valuable the gem will be when you break the checkpoints.
Besides that the only reason you would want to break them is to make the game harder, which is exactly why they made them breakable.
Update: As mentioned by jonespm, Shovel Knight is now on Steam and there's an achievement called "Get the Point", which requires you
to destroy all checkpoints in a single stage.
Solution 2:
There are achievements on Steam related to these. (Get the Point and Checkpointless) But with no Achievements in WiiU/3DS it's probably just the personal challenge and tons of gems.