Pretty good as of episode two. They hide grovers CGI legs so often it's a bit comical. Percy should not have won the fight at the creek until after being strengthened by the water. Being a natural fighter and winning you first fight (with no training) as a 3 v 1 are different things. Mr. D should be a bit meaner, and Gabe should be a lot meaner.
TLDR: Percy is OP, D and Gabe are too nice, hiding CGI to save money, and some other character changes.
Shows promise, miles ahead of movie 6/10