I posted this as a comment on curseforge, but this seems like the proper place and I did a couple refinements:
The feline debuff to mining is massive, and, in my opinion, outweighs the advantages heavily. It forces an explorative playstyle as underground resources can only be found in massive caves or structures, or I guess using explosives. While I like that kind of playstyle, especially with explorer class, it could use a bit more.

Thematically appropriate would also be a short, intense burst of speed, as well as a general boost to movement speed.
Considering the dietary needs of felidae, the low maintenance mode is more gameplay than thematic.
Following thematic threads, however, a minor debuff of being an obligate carnivore would also be appropriate, though perhaps with an added advantage of gaining more from raw meat than usual (to around cooked level) and not suffering from hunger due to raw chicken.
Felidae also lack the sweet-taste receptor.

+Does not take fall damage
+Can jump higher while sprinting
+Has slight dark vision
+Scares creepers away
+Increased movement speed
+Burst of speed at the cost of exhaustion
+Raw meat more effective
-Can only eat meat
-Can only mine natural stone when there are at most 2 adjacent natural stones
-Has 1 less heart of life

Feline should scare phantoms.