like the style, and level design and the character design. like the way that when you collide with a object that it changes colour and show that you have collided and that other one spawn so you have to search.
could add a counter so that that you are able to know how many object that you are needing to collect as right now i thought that when you collect the first one i thought something was going to happen and didn't relied that you have to collect other object, also could add a small light that turn on to show that you are activating the light and this would work well with the game.
other than that really great start