Playing BTD 4
Gameplay is the same as in Bloons Tower Defense 4. There are no changes in the tower types, tower upgrades, ranking systems or balloon types. The main differences between the core version and the expansion lie in other areas.
There are three major differences between the core version and the expansion pack. Firstly, you have four new tracks of varying difficulty with each having five difficulty levels inside. The Sandy Spiral Track is for beginners and has two tracks running side-by-side which meet in a spiral. Subterranean Sewers is more like a regular tower defense maze, Monkey Temple has balloons actually climbing up one side of the Temple and getting down from the other, while you're allowed to place your towers in between the two flights of stairs. Lastly, you have the Expert track, called Triangle of Insanity, which literally promises to drive you insane. All it has is a triangle floating in space with balloons pouring in through all three vertices. Extremely simplistic and very tough, typical of the entire Bloons series.
Secondly, you have the new Deflation mode in addition to the Sandbox and Apocalypse mode. This one gives you 50,000 money to start with, but doesn't allow you to earn any more throughout the game. Banana Farms are disabled, so no, those aren't an option either. Essentially, the level will allow you to deflate at a rate slightly greater than your money total, with the implication that the balloon quantity eventually overwhelms you while you remain powerless to do anything. The only problem here? You need to reach Rank 32 to unlock this mode, which isn't exactly something that you would think of when you use the phrase, 'all in a day's work'. Or you could just buy it through that disappointing Mochi Coins system.
Lastly, you have the Tower Specialties. A completely new innovation, this system allows you to select one Tower Specialty as a strategy, of which many are available. So, for instance, if you select Classic strategy, you get 20% off on Dart Monkeys, Tack Towers and Boomerang Towers and their upgrades while everything else costs 10% more. The same percentages apply for Support mode, which encompasses Monkey Beacons and Banana Farms, Munitions mode, which has Bomb Towers, Pineapples and Mortars, Vehicles mode, which has Monkey Aces and Monkey Buccaneers, Slow Down mode, which has Ice Towers, Glue Gunners and Monkey Glue, and the last and probably the best one, the Supernatural mode, which has Super Monkeys and Monkey Apprentices. However, this has the same problem as the Deflation mode, that is, these modes are unlocked one-by-one after you attain a certain undisclosed degree of mastery over all the tracks, so you have to work your way up to them. Or buy them with Mochi Coins again.
There's also a super special secret surprise (the developers clearly consider themselves as anointed aces of awesome alliterations), which can be found in the Monkey Temple track.
Regarding walkthroughs, well, the increase in strategy required for each and every one of these levels is astounding and frankly doesn't leave much room for a walkthrough. Focusing on the spiral in the Spiral track, the central part in the Sewer track and the point at which the balloons switch stairs in the Temple track should help. No one knows anything about the Triangle of Insanity because apparently they are in no position to have a sane conversation with anyone.
How it looks
The graphics have improved beyond the core Bloons TD 4 game to include relatively intricate designs, especially in the Sewer and Temple tracks. It doesn't really take away from the game because the intricacies add to the complexity in that you keep have to re-strategize to find the perfect place for your towers, but it can also be slightly distracting at times. As for the audio, the developers have chosen to provide us with the same track as in the core game. Let's just thank god for the mute button.
Worthy or not?
The expansion pack does certainly do what it set out to do, that is, expand on the core game. The same issues, that is, lack of a grid for towers and the insistence on the use and in fact the increase in influence of the Mochi Coins in the game, persist. Fixing one or preferably both of these would have made for a way better pack - the payment system is something which unfortunately is present in Bloons Tower Defense 5 too. All in all, this is a good expansion pack, but it won't keep players busy for long. Unless they get driven insane by the Triangle of Insanity, that is.