Shift + 1-9
I recommend you to read the "WA_Readme-3.6.29.0_Beta.rtf" file found in the main directory of worms installation.
• Replays (both instant-replays in offline games, and automatic game recordings): (introduced in v3.6.19.7, improved in v3.6.19.17, v3.6.24.1, v3.6.23.0)
• To pause playback, press S.
• To step one frame while paused, press S.
• The playback speed can be controlled with the top number keys 1 – 9. The progression is geometric in pairs: the keys correspond to 1×,1.5×,2×,3×,4×,6×,8×,12×,16×.
• Holding 0 allows setting higher coefficients: pressing 1 – 9 while holding 0 corresponds to 24×,32×,48×,64×,96×,128×,192×,256×,384×. The speeds are, however, limited to the processing capacity of your machine.
• Holding Shift while pressing a speed key or key combination will slow down playback, otherwise it will be speeded up.
• To set a "bookmark" at the current position during playback of a game recording, press M. When using "Playback at", the game sets the bookmark at the specified position and fast-forwards the replay until the position is reached.
• To rewind an automatic game recording to the current bookmarked position, or to the beginning of the replay file if no bookmark has been set, press R.
• To clear the bookmarked position and restart playback from the beginning, press Shift+R.