battery to maintain the date and time. If a console is unable to obtain an accurate date and time from PlayStation Network due to loss of connectivity and CMOS battery charge combined, games can be rendered unplayable on it, leading critics to decry this anti-cheat system as a form of always-on DRM and a threat to video game preservation upon discovery of this issue, known as the C-bomb, several months after the PlayStation 5's launch, as Sony was contemplating an equally controversial decision to shut down the PlayStation Store for previously discontinued systems that used it. In late September 2021, Sony resolved the C-bomb issue for the PS4 with firmware update 9.0.0, so that an inability to obtain an accurate date and time from PSN would only disable time-stamping of Trophies instead of blocking startup of games. Sony later resolved the same issue for the PlayStation 5 in November, allowing all physical and digital PS4 and PS5 games to run without any need for an accurate date and time reading from PSN, except for PlayStation Plus games, which require online verification to access them. PlayStation Plus PlayStation Plus (PS Plus) is a paid tiered subscription service that provides users with access to premium features. These features include access to online multiplayer, exclusive discounts on the PlayStation Store, the ability to upload up to 100 GB of saved game files to PlayStation servers, and three games available to download each month at no additional cost. These features are available to all subscribers, and are included even at the base "Essential" tier. The "Extra" tier provides access to the PlayStation Plus Collection, as well as a wide catalogue of 400+ PlayStation 4 and PlayStation 5 games. Moreover, the "Extra" tier also unlocks a catalogue of Ubisoft+ classics. The "Premium" (also known as "Deluxe") tier adds access to downloadable PlayStation, PlayStation 2, and PlayStation Portable games, access to limited trials of select games, and (in some regions) the ability to cloud stream certain PlayStation, PS2, PS4, and PSP games. For all tiers of subscription, users can choose between monthly, quarterly, or annual payment. Furthermore, all PS Plus tiers have the Game Help feature; a PlayStation 5 exclusive that provides spoiler-free hints and tips while playing supported games. Game Help can range from a nudge in the right direction, to a full video walkthrough which can be pinned to the side of the screen