Im not super bitchen at diagosing issues, but it does look over watered. How is the air in your waterr?
It may be just a shitty seed. Seems like no 2 are alike. Everyone who grows from seed has had a suicidal seed. There just isnt enough Prozac in the world to cheer them up. I grew a Northen Lights seed that grew dark purple. It never got past the size of a small soccer ball. I pulled it because it was a quarter the size of its peers and just couldnt get its shit together. I grow in a DWC with mild nutes, a lot of air, good temps, and great lights. Some seeds just suck... Now, in saying all that maybe its something you can fix.
It looks like it could be a viable plant. It lools like you planted it in a brownie. I your mix looks pretty wet. What is it? Make sure it drains properly, and your arent over watering it. You definatly CAN over water
I hatch more seeds than i expect to grow now. I expect to have some of these slow fuckers and i get rid of them. Its not worth thr heartache. Im kind of taking that to a new level this round. Germinating 12 seeds for the 8 best seeds. I have no room for stragglers this time