Try lowering the cycles. It could be one of those games that don't like running too fast.

Here are some important entries in dosbox.conf

output=direct3d

machine=vga
captures=capture
memsize=63

frameskip=1
smartupdate=false
aspect=false
scaler=none

frameskip=1
smartupdate=false
aspect=false
scaler=none
tvmode=false

core=dynamic
cycles=90000 (yes, should be ninety thousand. Machine is a p4-640 (3,2 GHz)
timesynched=true
showcycles=false

svgachipset=s3
videoram=131072

As long as there aren´s any enemies, the speed is mostly bearable. Enemies and especially water / lava can make it unplayable, but for the most time, ROTH is not a shooter.

To install and run any games, I do not use any frontends but the [autoexec]-section. For every single game, I have an according entry.

1. Install
If you can make an iso of the game-CD, do it. It helps to save some of the o so precious CPU-load.
Alas, I could make isos from the ROTH-CDs, but the imgmount does not work with those isos. All others games work, though, including normality, which is technically very similar to ROTH.

# GAME NAME
mount C "C:\dosgame\game"
mount d "d:\" -t cdrom
# The following would be better than the cd-mount, but does not work with ROTH
# imgmount d "c:\cd\game.iso" -t iso
c:
install

2. Play
After installation, this entry has to be modified.
Normally, games cannot be installed in the root directory c:
On your HD, you now should have a new folder
"C:\dosgame\game\game"
To play, you either have to change the path in the [autoexec]-section or you move the complete content of the now folder

If you copied all from "C:\dosgame\game\game" to "C:\dosgame\game", your entry in the [autoexec]-section should look like this:

# GAME NAME
mount C "C:\dosgame\game"
mount d "d:\" -t cdrom
# The following would be better than the cd-mount, but does not work with ROTH
# imgmount d "c:\cd\game.iso" -t iso
c:
game.exe

Remember to change Res to Vesa.