Appmon, which has already drawn favorable comparison with Rockman EXE/Mega Man Battle Network, invokes the Dark Web as a major setpiece. While EXE predicted the existence of the Dark Web three years early via its own Undernet, Appmon is working with a location that's already been implanted in the public imagination. The choice to house its overarching antagonist within the Dark Web is intriguing, as being the abyssal plane of the internet, it follows that the web's own "leviathan" would lurk there.
This exposition is coupled to other developments. Navigation apps have been going haywire throughout the town, creating a citywide panic, and Haru's classmate Ai is one such victim. After learning that she went missing while out shopping, Haru immediately volunteers to go search for her--a dramatic shift from his behavior in the first episode, and one that doesn't go unnoticed by Yuujin.
Like in the previous episode, Haru and Gatchmon overcome the monster of the week using Gatchmon's Deep Search function to pinpoint its weakness. (Not unlike the gamers at home googling Appmon weaknesses in Cyber Arena.) However, this episode established the fears that each episode would only boil down to Deep Search were unfounded. Haru accomplishes his strategy of the week--"Rotate"--by using the much-teased Applink ability, linking Gatchmon and last week's Messemon. One background point to this was that the final combination was shown to literally be more than the sum of its parts, with Gatchmon's base 1000 power and Messemon's base 500 coming out to 2000 as "Gatchmon Plus Messemon."
The power level pacing thus far matches the tempo of other Digimon series, giving our first Adult/Armor/Super in episode 2, but the pacing of story beats is entirely different. By introducing a direct subordinate of Leviathan and involving him in a battle with the protagonist so quickly, Appmon's functionally jumped ahead to episode 8 (Adventure) 14 (Tamers) 6 (Frontier) or 12. (Savers) This is a shift I'm critically receptive to--it's trimming the fat, which is what makes it so difficult to introduce Digimon to mainstream audiences in the first place.
One thing that struck me regarding this episode was the way Yuujin seemed to get subtly pushed into an antagonistic role again, in a subtler way than at the end of episode 1. Ai vanishes and becomes a motivator for Haru to track down Navimon, but then she turns up safe and sound with Yuujin later. It seems as though the series is pushing for Yuujin to be in cahoots with Cameramon, knowingly or unknowingly.