Counter-Strike: Source vs N.O.V.A. Legacy
Counter-Strike: Source
Counter-Strike: Source is the second installment in the incredibly popular MMOFPS franchise, Counter-Strike. Despite being a rather old game, Counter-Strike: Source still manages to hold its own in this day and age, with some even claming this game is so much better than the more recent Counter-Strike: Global Offensive or CS:GO. Unlike CS:GO, this game doesn't offer buyable skins and the most important thing - the community is definitely not as toxic as those you'd find in the CS:GO servers. Although the game modes can be rather limited, you can easily find some really good new ones in modded servers.So, if you're looking for the Counter-Strike experience without all the hate that most new players will get, this might be a good game to start.
N.O.V.A. Legacy
N.O.V.A. Legacy is among the best sci-fi-themed MMOFPS game on mobile of all time and it has inspired a popular new franchise, N.O.V.A. as well. In this game, you play as Kal Wardin, a veteran N.O.V.A. marine, who have been drafted once again into the Colonial Administration forces to fight against the alien invaders that threaten the whole of humanity. The game provides players with a wide variety of PvE game modes to play in, including an offline story mode, Shadow Missions where you get to fight aliens on a limited time battlefield, and Special Ops that pits you against various unique alien formations.N.O.V.A. Legacy also has a multiplayer mode that will allow you fight against other human players in exciting 4-vs-4 team deathmatches or the last-person-stading deathmatch. In addition to crafting and upgrading your weapons, customizing your character's Mobile Armored Suit is very easy and in-depth as well. You can add Cores to give yourself some nice bonuses to supercharge your gameplay.
When it comes to multiplayer shooters on the mobile platform, there are only a few that can go as far as to claim that it plays just like a console game - this game is definitely one of them. Granted that the graphics isn't as great as marketed, but the gameplay is amazing and you even get an offline story-based missions on this free-to-play app! It is as good as it gets!