This player uses HTML5 rather than Flash to play Youtube videos, enabling speed control. And maybe responsive sizing. There currently is no way, however, to enable the full-screen button.
Experimenting with launching the full version with Spanish captions turned on:
Full version here ; click at the top to accept Spanish, and "More..." at the bottom to expand the transcript.
Full-screen Spanish CC version here)
Embedded here with Spanish CC:
Trying a fresh video:
NOTE: the code feature seems to be broken, so don't try to store or document any html tricks here.