itch.io

Sure! The way I play has me hiding behind cover a lot and poking my head around the corner to fire all 3 of my shots (since some of them will die to enemy bullets) So items that make that easier would appeal to me. (I'm not so good at bouncing my shots)
Here's some ideas off the top of my head:

• Bullet Speed increase (passive)
• Temporary invulnerability/shield so I can charge around a corner safely (active)
• shield that blocks the first shot that hits you for a few levels (passive or active)
• staff that shoots a bullet that follows the mouse (active) (strong but requires focus)
• alt-fire follows the mouse (passive)
• staff that calls down a meteor at mouse position (active) (maybe too strong)
• Laser sight that shows how your bullets will bounce (passive) (good for unskilled players, useless for people who are good)
• shots bounce more than once (passive) (double edged sword)
• Shield(s) that orbit the player and block enemy shots (passive or active)
• movement speed (passive) (saw someone wanted this, so might be a good compromise as an item)
• immunity to traps (passive)
• teleport to mouse position (active)
• Nova/Explosion that stuns enemies through walls (active)

Here some less good ones

• Nova/Explosion on self that knockbacks projectiles like the club but all directions
• dodge roll (active) (lol)
• shotgun staff (active)
• rapid fire staff (active)
• staff that shoots a bullet that goes through walls (active) (maybe too strong)
  
• Energy Band, but instead of becoming exhausted, your shots become slightly inaccurate (for a spray and pray playstyle)
• Shots curve (passive) (you can curve them around corners or enemy bullets)  
• normal shots explode (passive)
• Alt-fire lights the ground on fire for a decent length of time, maybe still destroys missiles that travel over it (passive)

Also something you might consider if you want to push players to bounce their shots more is an enemy with a laser (like the staff) that only fires when it has direct line-of-sight