Very dynamic composition! Makes me terrified of this hero and..to enter the contest haha.
I'm assuming this is just the line art so far and you'll be rendering it fully later?
The face of the "giant" remains a bit too ambiguous but I'm sure it'll be cleared up when you're done. If I were doing this, I'd add some "forward moment/direction" to your piece by adding or moving spikes facing to the right as to give a directional force forwards rather than just up- as it seems like they're charging instead of just standing. Hope that makes sense!