Gori: Cuddly Carnage

Every level awards stars based on three criteria:
 

• Time
• Combo Score
• Difficulty

To earn all stars on every level, we need to complete each level under the time limit specified, achieve a combo score higher than the number specified, and complete the level on the hardest difficulty (which unlocks after completing the story). These don't have to be done all in the same playthrough of the level, so we should expect to play levels multiple times.

Challenges are unlocked by completing levels. The criteria to unlock stars depends on the challenge. Some are time trials, others require no hit runs, and a number of other specific goals. These can be replayed indefinitely to prctice, improve, and unlock the stars.