iiChantra is a crossplatform 2D action game with retro style graphics and modern gameplay. Despite its name iiChantra is not a clone of any Contra-series game, yet it tries to reproduce some gameplay aspects of them and add new ideas. iiChantra brings original graphics and contents although some characters and enemies may be well known for iichan.ru visitors.
iiChantra P.E.A.R. ДСО (Omsk) is a continuation of iiChantra P.E.A.R. Backstory from the menu presented in the game (second screenshot) is actually the plot of P.E.A.R. They share the same engine, developed by the same team and some of the art assets are reused, but the gameplay is different, and all of the ДСО levels are completely new. P.E.A.R is also based on a much earlier version of the engine and many problems that surfaced later on were addressed in ДСО, not newer version of P.E.A.R.
Thanks, added second video. By the way, do I understand correctly, that iiChantra P.E.A.R and iiChantra P.E.A.R: Omsk are actually different games that are developed separately? Or iiChantra P.E.A.R can be considered something like beta/techdemo, and iiChantra P.E.A.R: Omsk is just further development of the same game?
This gameplay video is not from the same game as screenshots and release date on this page. The video is from "iiChantra P.E.A.R" that was released in january of 2011, not "iiChantra P.E.A.R: Другая Сторона Омсквы". Here is a short video with gameplay from the right one to avoid confusion: http://www.youtube.com/watch?v=Dj2E_N8NSVo