Pollfish has apis designed for games(Corona SDK integrated recently). I am pretty sure, it won't be 100 questions which you can't finish ever and I hope Pollfish.com would be intelligent enough to know this that it's a game and not survey app.
Also, REWARD for watching videos are there, similarly REWARDS for filling 5-10 question survey can also be there! Believe me, ppl like being asked questions(not extremely random though). And it is a bit better than watching 1 min. REWARD videos.. where 5 ques survey can be filled in lesser time depending upon questions.