  We note that the remarkable EXPSPACE-hardness result in [G\"oller, Haase,
Ouaknine, Worrell, ICALP 2010] ([GHOW10] for short) allows us to answer an open
complexity question for simulation preorder of succinct one counter nets (i.e.,
one counter automata with no zero tests where counter increments and decrements
are integers written in binary). This problem, as well as bisimulation
equivalence, turn out to be EXPSPACE-complete. The technique of [GHOW10] was
referred to by Hunter [RP 2015] for deriving EXPSPACE-hardness of reachability
games on succinct one-counter nets. We first give a direct self-contained
EXPSPACE-hardness proof for such reachability games (by adjusting a known
PSPACE-hardness proof for emptiness of alternating finite automata with
one-letter alphabet); then we reduce reachability games to (bi)simulation games
by using a standard "defender-choice" technique.
