  Indium antimonide (InSb) two-dimensional electron gases (2DEGs) have a unique
combination of material properties: high electron mobility, strong spin-orbit
interaction, large Land\'{e} g-factor, and small effective mass. This makes
them an attractive platform to explore a variety of mesoscopic phenomena
ranging from spintronics to topological superconductivity. However, there exist
limited studies of quantum confined systems in these 2DEGs, often attributed to
charge instabilities and gate drifts. We overcome this by removing the
$\delta$-doping layer from the heterostructure, and induce carriers
electrostatically. This allows us to perform the first detailed study of stable
gate-defined quantum dots in InSb 2DEGs. We demonstrate two distinct strategies
for carrier confinement and study the charge stability of the dots. The small
effective mass results in a relatively large single particle spacing, allowing
for the observation of an even-odd variation in the addition energy. By
tracking the Coulomb oscillations in a parallel magnetic field we determine the
ground state spin configuration and show that the large g-factor ($\sim$30)
results in a singlet-triplet transition at magnetic fields as low as 0.3 T.
