@MrSillyheadSr'comment on YouTube(very helpful)
FYI you can abuse charm (especially the focus to charm skill as it works on a cooldown and not a chance) to get beneficial effects. I.E. the clapping skeleton will give you armor if you didn't have any and the necromancer will summon permanent allies for you.

This is my replenish: 1. Sacled up will make you and your weapon grow up that means use one hand weapon could be fast and more useful. Use that you could hit the Impostor that she can't hit back. 2. Brighe Burner and Hot Shot match very well. And be careful the Trailblazer is useless for Boss, so don't pick it. 3. Trick Skin, take it without thinking. 4. Emotive is useful in all Boss fight, because the Boss will hit it first. 5. The hand in Winkydink could hit the Boss that doesn't need you kill the Boss hands. 6. Personal Cloud could ignore the hegemony. So take it. 7. The skull guitar will interrupt all attacks of mobs, very powerful, but useless in Boss fight. This comment is has been synced to this vedio guide post in Steam.

Anyone who reads this post should not give up watching it just because it is a video. It is really useful. After watching the video, I only used the game four times to clear Overtime 6 and Overtime 7.

Hey, just wanted to say thanks so much for this video. These tips took me from uninstalling because I couldn't beat Overtime 1 to first-trying Overtime 4-thru-7 (yes, even 7!). There were lots of things I didn't know about, like the bananas and the free hats. If anyone else is struggling, I highly recommend giving this video a watch. Most important tips are the hat stacking (get that skill if you don't have it yet) and the Swomp/Tappi mentor IMO.