Yes, Mangalore's landscape look quite similar Kerala & Goa.
Though there are some similarity with kerala and Goa, by virtue of these regions being on the west coast, like food, with fish being the staple and coconut being generously used in all dishes. These regions get abundant rainfall and lot of coconut palms growing everywhere is probably another reason for Mangalore region looking similar to Kerala and Goa. Also another things is the red soil which is common in Goa and Mangalore. The similarity ends here.
Though Mangalore is a part of karnataka state, it is geographically, culturally, ethnically and linguistically very different from the rest of Karnataka.
One more distinctness is Mangalore and Udupi, two of the largest cities in Udupi & South canara have a lot of high-rises compared to other upland cities in Karnataka.
The twin districts of South canara and Udupi of which Mangalore forms a part is called Tulu Nadu. Tulu language is the most widely spoken language in this region, unlike Kannada in the other parts of Karnataka. Tuluvas are the majority ethnic group in Mangalore region, who have their own traditions which are very distinct and different from other people in Karnataka, Kerala or Goa.
So better not to compare Mangalore with any other region since it has its own uniqueness.