Mission 16: Over The Top
Turn Time: 45 seconds Enemies: 1 Commando (hidden), 4 Gunners (2 of which parachute in later in the mission), 1 Grunt Your Pigs: 1 Hero, 1 Commando, 3 Level 3 Pigs
This mission introduces 200 health Artilleries, specifically two of them on the two high areas of this map. The Grunt starts on the bridge spanning these two areas, and gets the first enemy turn - which is always to run to one and jump in it. The Commando, in the ? box up there, will occupy the other on the next enemy turn. From up here, the enemy will use their new-found skill with shell aiming to decimate your team whilst you try and fight back. OK, it's not that hard, but it's a lot harder than it could be. To stop this from happening, make sure your Hero and Commando get the first two turns, and use their Jetpacks (not the Hero's Special Ops) to fly up there and occupy them before the enemy can. The Hero should go first, and with the Artillery, blow up the bridge; this stops the Grunt occupying the other Artillery, but don't kill him as that will mean the first enemy turn will go straight to the Commando who immediately comes out of hiding and occupies the other Artillery. Your own Commando then jetpacks up, takes it over, and blows the Commando down to join the Grunt. From there, it's easy pickings. The Gunners will operate on your side as they will try to blow up the Artilleries, both of which earn you a medal drop (inside a circle of mines...) on their destruction. Of course, individually, the Commando poses the biggest threat so your non-elite pigs should go and kill him with their first turn.
Mission 17: Geneva Convention
Turn Time: 30 seconds Enemies: 4 Commandos (all at 30 health, in Medic Tents) Your Pigs: 2 Heroes, 3 Level 3 Pigs
This would be pretty difficult if the Commandos weren't at a measly 30 health. However, they all start in a Medic Tent, which restores 50 health for each turn they take whilst they're in there. So, each Commando will jump out on their turn with 80 health and start their attack. The Airstrikes you have come in incredibly useful here, as you can blow up Medic Tents and perhaps kill the Commandos inside with one use. At the end you may have one or two left, which shouldn't be too difficult. Remember that you're down to 30 second turns now, which can make a big difference.
Mission 18: I-Spy
Turn Time: 30 seconds Enemies: 5 Spies (all hidden) Your Pigs: 2 Heroes, 3 Level 3 Pigs
This is quite difficult in comparison to the missions that have come before. All of your enemies are invisible on the mini-map at all times during your turn, and start hidden in trees (of which there are a lot on the map). It's a good idea to play through this mission once or twice to get a vague idea of which trees some of the Spies are hiding in so when you retry the mission you can start by immediately revealing enemies. Thankfully the enemy Spies can't use Pickpocket, but they can throw Poison Gas grenades with ridiculous accuracy, TNT you, and routinely take off 40 health with their Sniper Rifles. Saboteurs can help move enemy Spies out of effective range using the Super Shotgun/TNT, Airstrikes will likely reveal one or two Spies if you bombard enough trees with it, and can be used to crack open the armoured box in the map which contains two medals. If you use up your Airstrikes otherwise, a Super TNT charge drops in later in the map which will achieve the same effect (or can be used to instantly kill an enemy). The map is horridly laid-out, too, which doesn't help.
Mission 19: Chemical Compound
Turn Time: 30 seconds Enemies: 1 Commando (hidden), 2 Pyrotechnics (one in the Pillbox, another parachutes in onto a ledge later on in the mission), 1 Spy (hidden), 1 Surgeon Your Pigs: 2 Heroes, 3 Level 3 Pigs
This mission has a strong opposing side and goes on for a long time so don't be surprised if you fail this mission multiple times...getting the survival bonus is rather difficult too. You have a long icy path to follow before you get to the main area of the mission, which is the compound at the end with a load of chemical trucks in it - blowing all these up yields you a medal. Nearby here is the Commando, the Surgeon, and the Pillbox with the Pyrotechnic in it...who will immediately leap out and Mortar you from a distance. The moment you get within range, he hops back in and takes potshots at you with the Heavy Machine Gun until he runs out of ammo, where he'll leap out again and resume using Mortar/Bazooka. The Spy is hidden on the higher ground nearer you, nearby an Airstrike crate in a small densely-packed minefield.
You will want to start by, ideally, using something to knock the nearby Spy off the higher ground. The Surgeon's Grenade and Hero's Bazooka works well for this (providing you can make them connect with him). Once the Spy is in the icy path, he's a lot easier to deal with. The Pillbox can be taken out fairly easily at range whilst the Pyrotechnic stands on it with an Airstrike or a couple of Bazooka shots. The Commando might give you a bit of trouble, but a Bazooka shot or an Airstrike will deal with him until you can get within close range to take him apart with TNT. The Surgeon's only real threat in this case is the Tranquiliser shot and the occasional Medicine Dart/Ball. Prior to this, he will simply try throwing Grenades at you (fruitlessly). Once you're in range he'll go down quickly. This then leaves the Pyrotechnic which drops in later in the mission - one long-range explosive will knock him off his platform, and then close-range pummelling once he's on the ice will soon sort him out. You might want to leave the Surgeon alive whilst you do this, as a medal drops down onto the platform that the Pyrotechnic drops onto once he dies.
Mission 20: Achilles Heal
Turn Time: 30 seconds Enemies: 8 Surgeons (four of them drop in after a set number of turns), Your Pigs: 2 Heroes, 3 Level 3 Pigs
The aim here is to kill the first four Surgeons before the other four Surgeons parachute in. This is harder than it sounds because firstly they have a Mash Tent on their side of the battlefield, and secondly, their vast array of healing weaponry. So, let rip with your Airstrikes immediately. Your other pigs should make their way across the battlefield and get stuck in with TNT and other close-range weapons. A Spy can turn into a pseudo-Surgeon if he gets the right items from Pickpocket, which helps tremendously if you fail to kill the Surgeons before the other four Surgeons drop in. The mission does become a lot harder once they arrive, so you may want to restart the mission.
Well done on completing Bellyopolis, and you get another 5 promotion points for doing it! Once again, the missions take another step up in difficulty, but you've only got 4 to go before the final battle.