Can we agree to call them “achievements”? I know we mostly do, but some games seem to re-name things in the interest of being special snowflakes. Now that the largest systems in the North American market are using the same term, let’s accept that as the proper English word for those gaming account celebratory decorations.
Giving your new game a different term for the sake of being different creates verbal confusion and is just asking for really annoying forum discussions in which simpering trolls rack up post counts by “correcting” everyone for not calling them “trophies” or whatever. Double points are deducted if you have multiple and similar terms, triple points if you use “achievement” as a subset of “trophy.” You get a pass if there is a good reason for using a different word. Games that pre-date this consensus can keep calling them badges, deeds, etc.
I do not think we have a similar consensus on “guild” yet, especially given the range of games in which “guild” feels inappropriate. It would be fine in The Lord of the Rings Online™ (“kinship”), but not so much for City of Heroes (“supergroup”) or EVE Online (“corporation”). Maybe for some instances in each. “Group” seems pretty standard; CoX’s “supergroup” unfortunately leaves them with “team.” “Clan” seems a strong competitor between games but rarely within them. Let us not get into “character,” “avatar,” and “toon.”