My Thoughts :)
Found 21 friends, and my first thoughts are that add a button (perhaps the SHIFT key) to make him sprint instead of him speeding up over time because this gives more control to the player.
-Consider creating an up and down walking animation as I think it would give more life to the protagonist.
-Consider setting up a menu screen where you can Play game and Quit the game too (it can be that minimal) + it could set the mood.
-I liked the introduction with the images but unlike the last few pictures depicting the boss of the Gordon City Bank they're aren't coloured, consider doing so but thats entirely up to you :) you might be going to a black and white theme to reflect a depressive state. (If so then maybe as they get more friends the colours of the town become more vibrant. OR people who you aren't friends with are colourless but when you become friends they become coloured, just an idea that popped into my head.)
-Also consider adding a town theme song which plays everywhere there isn't a music box (if you want to be thematic you can make it a dummed down version of the music box tune so when you find it, it sounds more invigorating).
-Whenever I get to the edge of each side of town I run into the wall and are teleported to the middle of the screen. This feels a little jarring so just set up some normal collisions there and consider having something physical in the way so this barrier is more believable in the game world.
-As with all game of a similar style, such as Castle Crashers its hard to perform certain tasks from that perspective. For instance putting in the basketball was quite hard due to the nature of the style of game you've used. So consider thinking of other approaches that rather than show weaknesses of the style embrace their strengths. Every game style has weaknesses and advantages.
- Finally think of what you could say with this artwork (game), friendship is a pretty important part of all our lives. Does something happen and he has to rely on his friends for help? Do they all disappear the next day and you have to find out what happened and save them? etc.
Apart from all that I think these are the humble begginings of something really cool. I'm glad you've posted your game here because player feedback is arguably the most important aspect of learning how to make your games better. But make sure to get more than just one opinion because unfortuantly some people won't like your finished game, while others will you have to focus on this group. As long as you make it engaging (it doesn't have to be just fun) you'll make the most out of what you've made.
Stay Determined :)
Just a side note, THANKYOU for making it playable on browser. I think what really stops people from playing demos of games on any website if if they have to download to play anything. So always have a demo online linking people to your full game if you make one :) Good work.