Much has happened since the launch of Doom 3 in 2004. And more than it rained remembering when his previous installment came out: Doom 64, in 1997. Luckily now the id Software saga is back in top shape thanks to reboot from DOOM in 2016 and the content that does not stop receiving DOOM Eternal
In addition, this saga with almost three decades of history (it was born in 1993) is very given to the experiments or at modifications, having in this case a mod for Doom 3 that pays homage to classics What Against, Metal Slug, Castlevania, Strider and Ninja Gaiden, in the words of its creators (Atomic Armadillo Entertainment).
Baptized as Hard Corps, which in itself is already a nod to the Konami Contra, we ran into a run & gun from scroll tremendously dark side, in the line of what the aforementioned 2004 work by id Software supposed. This is its most up-to-date version, as can be read from modDB
The result, in plain view, is curious and an excuse to play Doom 3 from a totally different perspective and with obvious changes in its mechanics as it is now in a world in 2.5 dimensions. You can free download and play if you have a copy of the original from 2004. On Steam it costs 4,99 dollars, eye.