I like the idea however there were a few problems. there doesn't seem to be a way to undo a move so if you softlock yourself your run is done which for this type of game is very easy to happen. also since the player can move the line orthogonal (up down left right) it would make a lot of sense if the player could use the arrow keys (and maybe even wasd) to control the line. also doesn't make sense that you have to click on the yellow one to start instead of  connecting immediately. these are all minor things to fix but could make this game a lot better. I presume I reached the end as I got to a point where I connected back to the yellow line and nothing happened. last thing I'll note is that when a dot only has 1 dot it can connect to it makes it so a loop can never be done with said dot and so the inclusion of it often feels weird.