I think a stage select would also work wonderfully.
Besides the classic contra machine gun and spreadshot, what other weapons do you have planned? Anything from metal gear or commando 2-4? And is a customizable loadout something that might be possible in the future, where the base weapon changes with some tradeoffs?
homing shot is in the current subscriber build and I really want to add a flamethrower as a power up. I have also been working on screen clear bombs to use.
A customizable loadout is a fun idea but since this is my first game I am going to need to keep the weapons simple and straightforward for now. Maybe when I am better at making games we'll see Goop Troopers Tactics!