Thank you for the kind comment, reading that you enjoyed it with your brother brings us joy! And congratz on beating the game, not that many people manage to do that, it is quite hard to get used to after all, and there are quite big difficulty spikes too! If you want an extra challenge, you can try finding the secret too! Its in the pre-boss level and not that hard to find, but really easy to miss!
I actually never heard of heart star, but it looks pretty similar, didn't think there would be a similar game, but the concept is not something overly unthinkable so it only makes sense!
Once again, thank you for playing and enjoying our game!