Some of the most fun I've had playing video games was sitting on the couch with three other friends and playing Goldeneye, Mario Kart 64, Super Smash Bros, Halo, Timespliters, Fusion Frenzy... etc. Never mind the complaints about screen peeking, or the super-low-def TVs of the era, these were deep, rich gaming experiences that combined all the best parts of teamwork and cutthroat competition. I'm especially fond of the Halo 2 system link LAN parties we had, where we had two teams of eight in two different rooms in the house, battling for hours on end trying to capture that last flag. Having your buddies in close physical proximity meant you could quickly and efficiently communicate and coordinate, and the crazy, ambitious plans we hatched on the fly (and occasionally actually pulled off) stand out to me as some of the most rewarding gaming experiences I've ever had.
But of course, something happened when headsets and online play became popular among console users. The value proposition was obvious: play multiplayer all the time, without having to actually get them over to your house (a non-trivial problem if you're too young to drive, or live in a rural area, or just don't have many friends). You can even use a headset to talk to your teammates and opponents - just as though they were sitting on the couch with you! Except... it's nothing like that. There is a coldness to talking to a disembodied voice over a headset, something the social animal can't connect with. Me and my friends chattered over our headsets, but it rarely became as raucous as our interactions on the couch. Those rare times when we finally planned around our busy adult schedules to find time the couch to play Halo: Reach or Super Smash Brawl proved the point - we hadn't simply outgrown it, it was still way fun.
Halo 4 was the last game we spent a lot of time playing split screen on, but we were eventually forced to quit as the framerate was unplayable on newer map packs. Clearly, the era of split screen was dead - only Nintendo caries the torch on. It's a frustrating loss.
The last few years have seen me become a lot more involved in board games, tabletop RPGs, and miniature wargames. The primary driving factor for that was my craving for physical human interaction when gaming. I was suprised by how lonely I felt even when I had a regular group on VOIP to play League of Legends, or a community of friends in Planetside 2. I won't undersell how much fun I had with those people, but they were disembodied voices to me, and I couldn't connect the way I could with people on the couch.
Manned Mars exploration is technically feasible - I have no doubt we could send someone there by 2020 if we put in the effort. But we would eventually abandon it for the same reason we abandoned manned exploration of the Moon. It's just too difficult to safely transport living human cargo to and from other worlds for anything beyond small exploration expeditions.
If trasnshumanism eventually becomes "a thing", if we manage to shed our biological shells and take on forms that are more at home in hostile environments, THEN we might see a blossoming of space exploration and ultimately colonization. Space is too vast, other worlds are too alien and we are just fragile bags of meat that need lots of external systems to maintain life (pesky things like "breathable atmosphere" and "food"). We fairly regularly and cheaply send robots in our stead. If we eventually "become" the robots, then yes, we will have manned space exploration of a sort.