I'm a The Last Stand 2/Zombie Blitz fan, those games are pretty nice, TL2 is a more older style zombie defense game, while Zombie Blitz is a more modern one. They work a lot like cod zombies if it had waves and a proper shop, allowing you to kill incoming zombies to gain cash and exp to unlock perks and gear. Zombie Blitz also has this cool spin off called zombie stories, which are basically story games mixed in with the game play of Zombie Blitz. You can go first or third person in Zombie Stories.
No need to explain those games, i have 4 year of roblox gaming, i have probably played or at least know every single game on the front page(even the ones that appear in the "see more" (no flex or anything)