Hey, it's not that bad! Not the greatest, but usable.
I wasn't sure where Mimikyu's stats would go but from what I see I think it makes sense. Decent Attack and Speed (its faster than Pikachu, definietly hits harder), low HP but decent to high defenses (plus its Ability providing a free hit), and the same Special Attack stat as Pikachu (curious if that's intentional).
STABs are best you can get for a Physical Ghost/Fairy. Wood Hammer, Slash, Thief/Payback, and X-Scissor are interesting coverage. It also learns a lot of Special Attacks, guessing trying to copy Pikachu, though I don't think Pikachu learns Psychic, Shadow Ball, Dark Pulse, and Dazzling Gleam; maybe Alolan Pikachu. For utility it gets Hone Claws, Pain Split, Will-O-Wisp, Protect, Light Screen, Substitute (that's probably a bit meta for it), and Swords Dance (not to mention Splash for that Z-Splash). Egg Moves add more utility with Curse and Destiny Bond.
Not sure if it was worth the mention but it also gets Mimic and Copycat (which isn't the same, Mimic copies the opponent's last used move when Mimic was used for the rest of the battle while Copycat just copies the opponent's last used move).