undefeated spider was made as Kong-exclusive, but if Kongregate wants to self-destruct then perhaps it goes to steam.

There is also a sequel to undefeated spider. Did the spider ever say to you "I over 9000 skills, fool!"? It was a euphemism - the spider has millions of skills.

this is
The Spider's Web:

(these images are outdated by a couple years but the general idea remains the same. There is also a stat-sheet skill leveling system for all skills unlocked in the skill trees. Basically the passive skill trees replace tomes, the the active skill grids replace items. There are other differences as well, such as facing multiple enemies at once, hero-ghost party system, world map, and much more - but my pride is the skill system)