Yes, Samsung Metro XL does support the Marathi language.
Yes, you can play youtube videos on this phone.
Samsung Metro XL is a 2G mobile phone.
Samsung Metro is the better phone if we compare the specifications.
01) Metro XL does have 2MP front camera while Nokia 3310 does not have front camera.
02) Metro XL comes with 2.8 Inch display while Nokia 3310 has 2.4 Inch display.
Both phone comes with standard 1 Year brand warranty but Nokia 3310 comes with replacement warranty.
Yes, you can adjust brightness levels as per your rquirements.