Hi Anamik if you want some tips on polish you can take a look at my WIP over on the WIP thread (x9/vanilla SuperAwesomeDungeonCrawler) give it a try and you will see there are hundreds of things you can do to make fpsc look a lot better, custom textures and shaders are good but shaders can eat 10-20fps out of your game, so well made textures and well placed lighting to me is more important as my Art Design allows me to disable shaders Entirely.
My philosophy has always been to keep testing, updating,testing, updating until IM happy, be harsh on yourself, when your testing and you see something that you think people would complain about or just looks ugly or can be done better, quit the game, fix it, carry on testing, everytime you see something that can be improved, improve it and retest, eventually you will make it to the end of your game having tested and fixed everything.
If you do use shaders remember you need the appropriate textures and with some of the newer shaders some textures need to be within others as a sub channel mask, so researching what textures you need and for what shaders is important, as is deciding what shaders to use with which items, if you choose a specific shader for say static objects, make sure ALL objects use that shader and ALL objects have the appropriate textures to make the shader function correctly.
In todays era of indy a game doesnt neccesarily need to look AMAZING it just has to play well and look like effort was put into it, its design was thought out, its story is engaging, well paced and occurs at the right moment, the game play is enjoyable and not repetetive, etc etc get a group of people or use the WIP thread to test it, take on board what they say, change, update, re release and keep repeating the development cycle til your at a point where your game stands out against the competition and gives people a REASON TO PLAY IT| thats probably the hardest thing to do, I went with a unique art style and different approach to making an FPSC game that made mine stand out and get people to download it just to see what the hell it was about! it made people want to play it and thats half the fight won right there.
Use unique assets, create custom media, content, sound effects etc, make ur game unique. Think about things like sound design, interactivity, pacing, theres so much more to game design than building an interesting looking level and populating it with things to pick up or shoot, you need to give the player a reason to shoot the things, a reason to pick up the things, a reason to explore and look behind cupboards, you gotta build a world the player wants to keep going through, that makes them want to see whats next.
And I like the graphics in your trailer but like 80% of the trailer is graphics and like 20% is gameplay, you need to showcase the best moments of your game in the trailer, entice people in, make them want to play the game, if its all just title credits for YOU as a developer it doesnt achieve its desired effect.
Hopefully this all helps you, I mean by no means am I some authority on game design, everything listed above are just conclusions and decisions I came to by myself during the course of developing my game, if you take a look at the game, see that theres only a small amount of gameplay (maybe an hours worth) then factor in that hours worth of game play took around 6-9Months to create, you'll get an idea how long it takes to develop something with a quality feel to it.
smoke em if you got em