The readme file states that the map was made on the 2008.12.16, while the date when this SpongeBob SquarePants' episode called House Fancy (season 6) came out, according to Fandom, is 2008.06.06. Considering this and the fact that the build time of the level, according to the readme, is "3 days (+ 3 days of testing, repairing,....)", PICTISH_RUINS could have been easily inspired by the scene quoted above. At least this is what this level instantly reminds me of a lot — the charismatic geometry of these somewhat random, but also very elegantly shaped platforms, with items placed on them like if they were exhibits, really does recreate this feeling for me.
However, the name of the map, PICTISH_RUINS, involves something entirely different — some ancient ruins of the once existing civilization of the Picts who lived in what is today Scotland (en.wikipedia.org/wiki/Picts). The level also reminds me of mobile Open Arena's OACMPCTF1 due to the presence of numerous green broken-line-shaped slopes.
As for the item placement, this map has a lot of valuable power-ups (Quad, Battle Suite, Haste, Invisibility, Regeneration) that are well spread around the map, in my opinion. It requires some effort to pick them up here, but it's always well worth it. QD, Invis and BS being in the air make for at least some minimal challenge and engourage active participation in the match which gives more dynamism to the gameplay. While the custom sounds of the start of power-up action introduced by PICTISH_RUINS are not my cup of tea, I truly like the custom pictish texture of the Quad Damage, and I think it goes well with the title. However, I find its placement above a BFG, just like the placement of the BFG above the Haste, to be questionable, as when combined together, these three items can easily overpower any player or even bot. The same goes for the two BFGs located approximately close to each other on the relatively small bottom floor.
Despite this, all the regular weapons except the LG are present, and the BFG serves as a bonus; the map has an MH and a YA, and most of the weapons and items are properly and wisely distributed, even though it's something that is very difficult to do on a box map. The SG tunnel on the bottom floor gives a Quake II feel and creates an impression of finding yourself on (literally) an underground level, you might even think that there's one more floor on the level 😉
In fact, I don't really understand all the unconstructive criticism that is addressed to Bret C. Sheppard's releases, I guess they're just underrated becuase of their unusualness 😜