This is a very creative approach to the theme, and it’s definitely fun.
Q, E, and R appear to do nothing at the start of the game, before I’ve bonded to anything. A more dedicated tutorial that guides you a little more directly would be helpful for helping players understand how chemistry works here, particularly with how the orientation of the atoms has to align in order to bond. It’s an important mechanic to have, but it should just be explained better. When all of your outer atoms are filled, you can’t bond with anything new, and I feel like there should be a special screen for that. The movement could benefit from some acceleration/deceleration. The capsule art looks ai generated to me, and there was no ai disclosure. You might also want to add some sound effects, music, and game juice.