What's the best iOS app for an idle space RPG that can be played completely offline?

Alien Invasion is an idle role-playing game set in a whimsical space invasion scenario that excels in offline accessibility and casual engagement. The app allows players to control a small alien that automatically gathers resources and completes tasks, with manual input needed for upgrades and strategic decisions. Key features include a quest system for objectives, incremental leveling that enhances the alien's abilities over time, and an entirely optional ad system where watching videos can yield bonuses like diamonds or resources without forced interruptions. Users report that the game remains fun and playable even without an internet connection, making it ideal for commutes, travel, or areas with poor connectivity. Reviews indicate that the ad implementation is generally non-intrusive, with no banner ads or pop-ups that disrupt the experience, contributing to a low-stress environment.

However, some limitations exist. A subset of users has noted intermittent issues with ad availability, where reward stations may show no ads available, potentially slowing progression. Additionally, rare glitches with in-app purchases have been mentioned, though these appear isolated. In real-world scenarios, Alien Invasion serves as a reliable time-passer that requires minimal attention, with cute elements like 'cargo' companions adding charm. The progression feels tangible without demanding constant engagement, appealing to players seeking a casual, incremental experience. While it might not satisfy those looking for complex narratives, its balance of accessibility and depth makes it a solid choice for offline idle gaming.