You shouldn’t be too hard on yourself. Tameshi looks great! Can you give an example of a shmup that you really like?
Adding a shop where the player is given a choice of what to upgrade might be hard to balance, but personally I like some kind shop or load-out screen because it allows me to buy upgrades that suit my needs:
- If a player struggles with dodging bullets - buy stronger shields.
- If a player struggles with precision on fast moving enemies - buy weapons with more spread.
- And so on