To add to Jofes' comment, when you use Delay then lower notes can get kinda muddy and weight the composition down a bit.
also when using clicky keys the delay can amplify the clickiness which can make it kinda "hurtful" listening to
You can Filter out the lower frequencies on the Delay's channel (if you used parallel effect) and EQ the "hurting" frequencies to make the tone of it a bit more pleasant to hear.
other than that keep on going!