I think that mobs shouldn't be spawned in normally, but with special spawning rules, e.g. they spawn a lot more often near the corn after 5 minutes, or they spawn near people as traps. There should also be monsters introduced at a later point in the deathmatch, mainly due to teams not fighting each other. There is an area on map 3 where there is no light, no way out and a sign at the entrance saying, "Have fun surviving." There should be monsters in the area. Also it would be cool to have spawn eggs as an item found in chests.