Hmm, and I thought I was getting too old for concrete work…
Simple one first: Break out all the cracked stuff, and sweep it clean, NO DUST left behind. Set a bunch of Tapcon screws into what is left, leave them a little proud of the surface. You can add a length of form wire, wrapped around each screw. Next, there is a product we used to call "Milk". It is a latex liquid that causes new concrete to stick to existing concrete. Spread this all over the old concrete. Mix a bag or two of sacrete @4000psi stuff. Mag-trowel it in place, and even add a slope to it. can be left alone after the mag is done ( better footing/traction) or use a steel trowel for a slick ( and I mean SLICK) finish Be sure NOT to run any loads across this for at least a week, two would be better.
The HARD way. Hammer it out. Add rebar dowels and a few rebars down into the foundation. These should have bend to them, tie that to the dowels. Add the "Milk" to the foundation slab. Mix up a batch of high-early 5000 and place. Mag trowel and add the slope you want. If this was a bigger area, I'd add either a foam expansion piece between the new and the floor slab, or an asphaltic one if it is outside. Concrete is a bit like wood, it will "move with the seasons ( look at the local roadways) and the expansion will cushion some of it.
Just my $0.02 worth….