that's great, nice tweaks, I like how it's all coming together!
A few general comments first:
- make sure that the silhouette is clear, so for instance, at the beginning, the blue guy's hand is a bit lost in front of his body at x983, plus the key tip almost touches his left hand; x1007 on the other hand is nice and clear; around x1066, the key is kinda hidden, lost between the car edges of the back, plus the hand forms a tangent with another line of the car. I would lower the hand a bit so the hand is in front of the lighter car shape above the back tire (see image). Same around x1092, the key is overlapping with the red body and I would keep that clearer as well. Another one would be around x1130, where you could separate the legs and non-key arm a bit. The head/arm/body parts feel lumped together visually. Last one would be when he raises the key. The only clear part is the hand and the key, but the rest of the arm disappears in front of the body. It doesn't help that the whole character is blue. But you could tweak the pose so that the arm shape is clearer.
- red guy silhouette on x963 could be clearer for his arms. His right wrist gets lost in front of the left arm
From a technical point of view:
- it feels like the blue guy has IK arms; make sure that there isn't too much body/elbow movement while the wrist stays still. You will also want to make sure that there are arcs in your arm movements. Since it's not FK, IK arms tend to move around in a linear way. Good example would be when the blue guy raises his arm with the key at the end. It basically goes just straight up. The timing is also even. You will want to put a bit more character in that arm movement. Is he defeated when he brings that arm up? Is he doing it quickly to signal "Hurry! I need to get home!" Etc.
- I think the red guy hits the car a bit strongly at x1080; is that the intention, that he really jumps in front of the blue guy? If yes, then the body stops a bit too quickly, I would soften it a bit, add a bit more recovery with maybe a little step and arms sliding on the car for the right balance
Other than that, the timing is great and the ideas are clear. As you mentioned, it's a first pass, so for your next pass, add more breakdowns and really finish the timing of each movement. As you go into splined keys, make sure that there are no sudden pops in your animation, which means your spacing is solid without sudden speed changes or stops.
Can't wait to see the ending!