Sucky is a descendant of the word suck, but can have a different meaning depending on the context, and the type of person using the word.
1) What a sucky day! -> bad, gloomy day
2) Get off my porch, you sucky fruitbag! -> derogatory usage
3) You want sucky sucky? Me love you long time -> translated from Engrish to English, this line reads, 'Want me to suck your dick?'