thanks for playing and for the kind words!!
really glad you enjoyed the difficulty curve. we spent some time balancing the bullet upgrades so it wouldnt feel static, so it means a lot that you noticed the progression !! i think we still need to make it a little better though, maybe less xp per upgrade initially or something like that to keep the challenge up.
it was a blast playing your game too. congrats again on the entry and thanks for the support!!