(J. Alex here) Going off of MindChamber's note, the general study of dynamism and foreshortening will certainly help with that.
Of course that's not just general studies, but maybe looking at artists like Sushio from Studio Trigger could help? (I'm partly telling myself that as well, with my personal artistic journey)
MindChamber
I don't think your work is lifeless, it's just really polished and clean.
I'd say go for some crazy perspectives maybe? get a little angry with that line weight :3
GrumpySheep
Thank you! I thought about that, rough lines are getting real popular lately