We have the most poor performance version of the "hien"...though it has good 20mm cannons on the nose.
I hope HTC will release more Ki-61 variants...
The Ki-61-I-Ko/Otsu (this early version is 250kg lighter than Ki-61-I-Tei, flight performance is better. 591km/h at 5000m, 5min31sec to 5000m)
The Ki-61-I-Hei (MG151/20 in the wings.) has good punch against buffs with some flight performance loss.
The Ki-61-II-Kai is better than Ki-61-I-Tei at speed/climb/accel with 1500hp HA-140 engine. 610km/h at 6000m, 6min to 5000m. and its 20mm is increased to 200 rounds each (Tei is 120 rounds).
The Ki-100-I is much better than Ki-61 at turn and accel with Ki-61-II's armament.