The wide angle distortion.. some like it, others absolutely hate it. I for one like it. Though I tend to straighten lines in my own shots more often nowadays just because I started to like abstract-ish head-on compositions, I still love the dynamic look of a wide angle pointed up or downwards! My advice would be to play with it some more. Now they're all shot from a low point of view upwards but I'd like to see some other angles for the sake of variation. Years ago I knew a website from a guy that totally nailed it, with the craziest angles you can think of (like a toilet stall shot straight down from the top), but I can't find it back
As already mentioned, the contrast is a bit high in all of them, but that's probably a matter of taste too. I like the shots!