These all feel a bit soft to me. Not sure if you've got technical problems in shooting, or if they're just overJPEGed or something.
LOVE the first one. What a great setup, what a great instant in time. The desaturated look works pretty well here, to de-emphasize the green shirt, so the joke is a little less in your face.
Second one is cute, but basically kind of formulaic. Doesn't really grab me.
Third one is quite nice. I like the distribution of figures across the frame, there's a good sense of balance here. Not sure about the vignette, but the b&w/sepia/vignette do play consistently together as a coherent look. Another look might have served just as well, maybe? The wide frame is somewhat cinematic, so another look would want to respect that, as this vintage one does.
The last one just feels oversaturated and meh, I consider it to be the weakest of the lot. Not BAD by any means (apart from the softness) but just a short of blah professional-ish shot of a bunch of kids who got dressed up to have their picture taken.