The Spiker is an alien defense structure that works like a regenerating proximity mine. It shows ten to twenty big spikes facing outwards in all directions. When a human approaches or the structure is hurt, all spikes are shot at once, causing severe damage at close distance. During a cooldown period, the spikes will grow back and a finishing animation will visualize that they are ready to be fired again.
The structure can be built on walls and ceiling and should have a roughly cubic bounding box (this doesn't need to include the spikes). The spikes need to be on a seperate mesh (or one mesh each) so we can hide them at once when the Spiker fires. We will also need one spike of average size as a seperate model that we can use for the projectile. If you are also animating, it would be desireable that the Spiker puffs up while it recharges and contracts quickly when it fires. (If you aren't doing the animation, make sure the armor looks soft enough to allow this kind of movement.)
This is probably the quickest near-finished high poly I seen so far. And it's looking decent!
So, some quick feedback:
Eyes need to be slightly larger and have a slightly bigger distance from each other.
The opposite goes for the mandibles/teeth: They should be smaller and closer together (more like on the concept). The reason for both is that I keep looking at the teeth and think "these should be eyes", because the eyes on the acid tube have an environment and location very similiar to this.
The shell looks rather sturdy. However, the Spiker would be relatively sensible (shoots on being damaged) and would have rather low health compared with other structures, but none of them has a shell. Therefor I'd prefer if this layer was thinner and textured in a way so that it does resemble a soft material as opposed to an actual piece of armor.
The (puffed up version of the) body without the spikes should roughly fit a cubic bounding box, which means that the model shouldn't be as flat. The small thumbnail on the upper right corner of the concept sketches illustrates a possible aspect ratio.
The spikes should be slightly shorter, maybe 50%-75% of what they currently are. (Note that you sticked to the concept here but I figured it was easier to change on the model than on the sketch…)