A few months back some Resident Evil fans got a hold of an earlier version of Resident Evil 2 dubbed Resident Evil 1.5. They were working on completing the game as it was a very early build that had many parts changed in the final version. A user by the name of Colvin started releasing information, so they just decided to release the game in its current state while continuing to work and finish it.
Here is there statement:
This here is an ISO of our work in progress build of the Resident Evil 1.5 restoration project. It is not representative of the current state of development of the non-profit restoration fan-project. For updates on that, please see the bottom of the file for suggested locations to monitor things or visit the YouTube channel http://www.youtube.com/user/MrBZork
The build you now have downloaded is a bit of an unstable mess. The instability mainly comes from a tiny experiment we were running on this very build and the build itself had the joke name "Magic Zombie Door". It's an old build and in no way representative of the current state of missing room implementation, restoration of broken elements, or addition of new content.
Many of the features you see in the build, as explained in our making of videos, comes from injecting pieces of C code that adds features and functionality that was broken, missing, or otherwise needed. There's a terrible bug we internally called "Air Jesus" present in this build, a legacy issue from the vanilla build, where inspecting objects will often cause ... undesirable results. This bug has since been fixed, but is currently present in this build. While, technically, the load feature works, the save feature's brokenness makes it pretty useless. These are also features that're fixed and will be working in the final release. There are also many stability issues that causes the game to crash or otherwise misbehave, most of these have since been fixed too. So unless there's a very Konami Code-esque approach to how you trigger a randomized and reproducable bug, please don't lose your breath attempting to report bugs to us.
Resident Evil and the Biohazard are property of Capcom. The project is an unofficial fan-effort, entirely non-profit, comparative to such other fan efforts as Street Fighter x Megaman, Megaman X Corrupted, Dark Biohazard, various modifications to other Resident Evil titles, and so forth. All with purpose and intents of a non-profit nature, and rooted entirely within what most would consider fair use and the healthier side of fandom - aimed exclusively at providing fellow fans with a glimpse into a world that once could've been and to enable them to revisit the world of Survival Horror once more in the way only the 90s could, whilst at the same time showing our own love and support to a franchise, platform, and decade we hold dear.
真修复就神了 
要是能搞个3.5出来就好了 