I looked at the decomp of the Flash version with JPEXS Free Flash Decompiler and analyzed the RNG in Quest 10 ("Collect 600 Gold")

In each step, a slime moves in one of two directions dictated by the current position of the slime as shown in the figure.

From this, you can calculate the probability distribution of the number of steps before all 4 slimes converge in the center, and the results are shown below.

steps,probability,cumulative
5,0.954%,0.954%
7,11.475%,12.428%
9,24.085%,36.513%
11,24.226%,60.740%
13,17.234%,77.974%
15,10.322%,88.296%
17,5.663%,93.959%
19,2.970%,96.929%
21+,3.071%,100.000%

Ah, interesting information here, was wondering how the slimes moved tbh