To reduce speed change performance (in game profile) to custom. Start game and tune cycles/power from general settings.
Other way is manual setup “expert settings”. You must be familiar with manual dosbox config. Here you can set
cycles=3000 or cycles=auto
Just play with values
https://www.dosbox.com/wiki/Dosbox.conf
If game runs slow it may be because you set wrong cycles, wrong sound card, but probably you need set correct cycles value
Just tried pickle wars. After I set sound blaster with 220/5/1 it works fine. I am in level 1 screen