Its actually based on either Halo 3: ODST or the MCC version. Halo 3 Xbox was dead a year ago when I checked it out, the MCC is a sad joke you get to pay to play (though yes its cheap), Halo: Online is where its at and I'll explain why: newer engine, massive selection of weapons, some new official vehicles, modding tools that already rival many console mods, dedicated servers are just becoming a thing, the community is growing everyday, PEOPLE ACTUALLY PLAY THIS GAME, built in and much newer gametypes, BSP importing is limited right now but if it goes past forge objects I'm down. Besides my shoddy ping; Its a lot of fun. Between this, Brutal DooM online, and SVEN Co-op I have my MP needs met, all for free.
About Halo: Online being a mish-mash of games; thats exactly what I was trying to create with Halo 2.5, a Halo that you tweak and play how you want. I'm very happy with what we have so far. I would prefer an editing kit as well but this is 100% better then the nothing they gave us before.
I might not have mentioned this, but a few years back Shawn showed me the website log files; Microsoft had suddenly appeared out of nowhere and downloaded the entirety of the H2MT, at least 30GBs. This was long before Halo: Online was a thing. Do you not see? They emulated our work. I'm proud and you should be as well Twin, I just wish we received some public acknowledgement what-so-ever.
[youtube]https://youtu.be/eDybXvNm2I4[/youtube]