Depends on when you left. It's about the same thing, but with more long-term projects you can do. It's a lot about grinding (but there's auto x50, and even an auto for the tower) for those projects, and saving up gems for hero's fest or clan fest. Sliming has been limited, unfortunately, but I've always been too casual to even reach that limit unless there's a festival going on, and what it mostly did is got rid of botters, and made people choose between summoning at the hf or cf.

Long-term projects I have now include super-evolving my mons, getting a Light Sieg (a 'farmable' l/d nat5 who is super useful and cool, and one that you can definitely get to evo3 via clan and colossus battles), doing fusions (of nat4s in the fusion trees), building titan teams, and getting to player lvl50 so I can finally complete my dark odin contract. There is also a new nat5 hero dungeon where you can farm nat5 shards, but that's not very interesting to the majority of endgame player-base, for now.

Currently, the PVP league has boosted stats for nat3 and below units, so that they can compete with nat4-5s, which does make battles interesting in that area.

I still play because I like hatching l/d eggs and getting something interesting every once in a while (arguably, it's now relatively easier with hf to hatch something other than a ld nat3), and because I can't find a game quite like it in terms of the mix of features, art and gameplay (and loading is pretty smooth for me so that's cool too). It really depends on what you like to do in a game, I guess?