Continuing the theme, one of the key indicators of a “bad” free-to-play game is the inclusion of timers. Of course, as with all other items on this list, timers can be more or less villainous--it’s a matter of degrees. Very few games, including Clash of Clans and Extrasolar (not a mobile game) handle timers well. Clash of Clans doesn’t prevent you from accessing core gameplay with its timer system, nor is the timer system excessively punitive. In the case of Extrasolar, the long breaks required between sessions are a key part of the game’s story and mechanics--not merely a tool to disrupt the player’s sessions.
The real issues come when games use timers as walls. Star Trek: Trexels, despite a loveable pixel art aesthetic and narration by George Takai himself, walls any actual gameplay behind several different sets of timers. You have to go through several different timers just to reach the core game--in essence, the timers are the game. The oft-reviled Dungeon Keeper remake shows another pitfall--excessively long timers. It’s hard to stay invested in a game when you’re only required to actually play it once every three or four days. Excessively long timers destroy any meaningful sense of progress for the sake of pressuring players to shell out their cash.