It took me a while to understand the game, especially that I could click on the flying items and the thief, but it was fun after that. Perhaps a bit more clarity on what things are and what they mean could be good.
What I found odd was the autofire, which was active for me almost 100% of the time from a certain point and eventually began stacking up faster than it was running out, with no reason to stack it since the thief makes it so you can't "idle" for long. This made the autofire upgrades useless and made the flying items have a 50% chance to essentially give me nothing. By the end, I had almost 10 minutes of autofire time queued up. Perhaps it could be made less frequent or some other solution could be found (lower chance the more time is already queued up?).
All in all though, this was an interesting concept. Nice work!