Help improving session length on cartoony gun game

Intro
Hi guys! I made a game called untitled gun game, advertised the game with 26 credits! The game constantly had players, however it had some failures. The session length was only 4.5min! Which is half of what it should be. Some people joined the game then left within 20 seconds. Most people left after 5 minutes of playing! I was looking for advice to keep my players engaged for my next advertisement. Or should I just scrap the game.

What I have done so far
I have added a quick Tutorial for new players, on top of that I have added random events that occur every 120 seconds to hopefully get players who played for 2+ min to stay.

Game Link: untitled gun game🔫[MINIGUN] - Roblox
Discord Link: untitled gun game

Please provide, more ideas to engage players and Critism


Is there a money system in the game? If so, implement a rewards system for how long a player plays, or do it for whatever currency you may use.

Yeah, there is! Theres a daily rewards system