As per title. Prefer something that still looks nice, preferably in 1080p or even 1440p, so probably more 2D or isometric than straight-out 3D. Something with nice bitmap drawings/cartoonish graphics that won't fall below 25–30 fps on this setup or is not fps-intense?

Genres: RPG, strategy, business sim, something with action, adventure, exploration, some thinking but not all-out mystery solver. Not really into MUD, but text-based adventure might be good.

I already have Civ 5 and Tropico 5, but I'm somewhat shy about trying to launch them, even though the laptop is within spec. Not really looking forward to extreme low-settings verions of AAA titles.

I've been looking at Eisenwald/Bastard, Ember, Commandos 3 and Desperados, but not really in the mood right now. Something a bit more optimistic in terms of climate/atmosphere would be in order.

Based on your experience, what would you recommend?

Play Brigador
https://www.gog.com/game/brigador

Tons of options, e.g.

excellent platformer : https://www.gog.com/game/rayman_origins
excellent survival game : https://www.gog.com/game/dont_starve_reign_of_giants
excellent, builder-platformer thing : https://www.gog.com/game/terraria

and much more if you're wiling to look at much older titles, e.g.

excellent business&strategy sim : https://www.gog.com/game/startopia
excellent themepark business sim : https://www.gog.com/game/rollercoaster_tycoon_2 (together with openrct2)
excellent adventure platformer : https://www.gog.com/game/psychonauts
best point and click adventure game ever conceived :

Maybe try the original Fable, though it is not available on GOG.