Very good idea. Has potential for expanding to bigger game.
Some critique (every other stuff is great, so i dont have to talk about them):
-Smoke autofilling is sometimes annoyingly slow
-The game could have more variety, some interesting enemy setups that require certain stradegy(and more enemy types helps this)(ofc i understand the time limit)
-the long sight enemy should show where he looks next, also maybe all enemies should show that idk
Otherwise rly fun and nice game