I’ll go with the monolingual definition I have, and try to translate it:
① 打ったり触れたりした時に,手に受ける感触。また,確かに当たったという感じ。「槍で突くと―があった」
the sensation received via the hand after hitting, touching etc.; the feeling of certainly having hit/made contact with something
② 働きかけに対する反応。「いくら教えてもさっぱり―がない」
a response to being acted upon/to the action of something
In other words, it’s not necessarily ‘resistance’ in the negative sense, and we could have attempted to reach that understanding by seeing which senses of each of these words are closest to each other:
The first three require something ‘coming back’ from an initial action, meaning that some sort of ‘feedback’ is received or observed. An ‘effect’, meanwhile, is what you could call the result of an initial action. In other words, these four words have in common a meaning that they require an initial action as their origin. This, therefore, is the actual meaning of 手応え, and not so much the typical slightly negative connotation of ‘resistance’, even though (from what I’ve just seen in another dictionary), it is possible for it to be a negative or positive sort of resistance or response, depending on the adjective that goes before it. However, it’s fundamentally just a response or reaction of some sort, whose literal meaning involves ‘answering/responding to a hand’, which is something we could have derived from the kanji.
To put it another way, in this case, what the speaker literally means is ‘on this test, I felt quite a response’, which is to say that it seems like the test ‘responded to’ or ‘resonated with’ the speaker, meaning that it went well. It also helps to know that 当たる, which is the verb in the first definition that I translated as ‘hit/make contact with’ above, is also the verb that one uses when one manages to hit a target or win in a lottery. The speaker feels ‘sure’ that ‘a mark was made’ (I’m paraphrasing the components of 確かに当たった, if that’s not clear) on the test, suggesting, once again, that some success was achieved on the test.