Along with three new protagonists, Kingdom Hearts: Birth By Sleep also introduced an entirely new type of enemies that act as a pseudo precursor to the Heartless in the timeline. One of these new Unversed brought a mechanic from the original game in a new package, with a bright color palette, simplified character model, and a new twist on the unique feature.
The Tank Toppler is infamous at this point among Kingdom Hearts fans, due to the way that these Unversed reworked the armored front mechanic of the first game's Large Bodies. There are a few enemies that have added their own twist on this mechanic, but few reach the level of frustratingly genius that the Tank Toppler managed to achieve.
Large Body Mechanic
Large Bodies appear early on in the series, taking a similar form to Kingdom Hearts' Soldier Heartless, but much larger and slower than their smaller companions. The trick to fighting these enemies is that the player is required to attack them from behind in order to do any damage, as the front is completely protected. This generally requires the player to let either Donald or Goofy to pull aggro on these enemies, or more commonly deflect an attack that gives an opportunity to get around the large figure.
Other gimmicky enemies in Kingdom Hearts have taken on this mechanic as well, such as the Defenders and Fat Bandits that appear later on in the original, as well as a few standouts in following titles. It generally comes down to the same strategy, where attacking from the front is useless, and usually leaves Sora open for a counterattack. However, the Tank Topplers are the first ones to add a more complex twist onto the mechanic, drawing from older Final Fantasy titles for inspiration on how players interact with them.
Tank Toppler's Twist
While the Tank Toppler has the same mechanic of not taking damage from the front, these Unversed will also grow bigger every time the player hits their engorged bellies. On top of making getting around the bigger target harder, if the player hits the front too many times the Tank Toppler becomes immune to damage and will begin to glow red. After tracking the player, these enemies will explode for massive damage that usually requires careful timing with late-game abilities like the sliding dodges Aqua masters in Birth By Sleep in order to avoid.
This explosion can be skipped as long as the player manages to continue attacking from behind, and the build-up is even reduced every time the wheel on its back is struck. So, the suicide attack isn't completely unavoidable, and the mechanic requires players to be mindful of not spamming the attack button wildly. Given that the "spam X" mentality can get players through even the biggest and strongest enemies in the Kingdom Hearts series, forcing the player to stop and plan their attacks is a big step for the game's design.
Designing For Fans
One aspect of the Tank Toppler that makes them stand out for fans of the classic Heartless enemies, is that their design telegraphs exactly how to beat them, and fans of the series should recognize how to fight them already. Large, round enemies like this had always required this style of combat at the point in the series where Birth By Sleep arrived. So, anyone playing with knowledge of previous games should have recognized the Tank Toppler as the Unversed version of the Large Body.
Then there's the matter of the large wheel on its back, that almost acts like a target to draw even new players who decided to jump in with Birth By Sleep first. So, most players would think they know what to expect at that point, until a few stray button mashes starts charging up explosion attack, which is bound to happen when Tank Topplers appear with other enemies. It's a relatively small change in the Heartless designs that makes for completely new combat experiences.
Kingdom Hearts: Birth By Sleep is available now.