Learn Finnish: Kukaan ei tasapainota tätä peliä.

Yes! It is made of the pronoun kuka (who) plus the enclitic particle -aan/-ään. When attached to kuka and paired with a negative verb like ei, it changes the meaning to "no one" or "anyone".

This lesson is about strict suffix ordering on verbs. Why doesn't tasapainota have any tense or personal endings?

Because it is part of a negative verb structure. In the present tense, the negative word (ei) takes the personal ending, leaving the main verb in the connegative form (just the stem). Any mood or enclitic particles would still attach to this stem, but personal and present tense markers are stripped away.

Why does tasapainota have a single t at the end of its stem when the dictionary form is tasapainottaa?

This is due to consonant gradation. The present connegative form used after ei always takes the weak grade of the verb stem. The strong double tt from the infinitive weakens to a single t.

How is the verb tasapainottaa built?

It is a derived verb. It starts with the compound noun tasapaino (balance), made from tasa (even) and paino (weight). The -ttaa suffix is added to turn this noun into a verb, meaning "to make something balanced."