More arena attempts

This is my latest approach to arena gameplay, I'm so set on arena gameplay because it works so well as a break from regular linearity. What I have in progress is an abandoned industry where the player has to wait for an elevator, while he waits there is a lot of space to explore and 15 antlions at a time spawning in any room the player can't see.

As you can see it still needs more detail. Other than that it's still suffering from two problems; there aren't enough enemies to pose a challenge that remains interesting plus they attack in waves because of the way I've set it up which leaves the player without any enemies for extended periods of time. The other problem is that I'm afraid the player will find a corner and camp there shooting anyhting that gets too close. I actually chose to use antlions here because they only use close combat and are relativly fast which I thought would mean they could chase the player and push him around, however they don't have a very strong attack and have very little health. I'm considering setting up an objective that requires the player to move around. For example, the elevator is broken and the player has to find its machinery and fix it. This kind of objective feels very pointless though and I'm afraid players won't enjoy it for that reason.