head to head
Suck Up! asks more than Garry's Mod, and the gap is variance.

Reads · Light / Casual
Source-engine sandbox whose community modes range from building to social deduction.

Variance · Bluff & Deduction
Improvising persuasion against AI characters whose quirks must be probed each visit.
Garry's Mod leans Reads (Light / Casual); Suck Up! leans Variance (Bluff & Deduction).
Garry's Mod leans a little harder on execution, though the gap is small.
Garry's Mod
Varies by mode; base sandbox is undemanding
Suck Up!
Talking and clicking disguises, no twitch layer
Suck Up! leans a little harder on reads, though the gap is small.
Garry's Mod
Social deduction modes like TTT involve humans
Suck Up!
AI neighbors respond to your words semi-adaptively per encounter
Suck Up! leans clearly harder on variance.
Garry's Mod
Hidden roles and player chaos in popular modes
Suck Up!
Each NPC's personality and reactions are unknown until probed
Suck Up! leans a little harder on optimization, though the gap is small.
Garry's Mod
Contraption building rewards systems knowledge
Suck Up!
Reliable persuasion scripts emerge and converge over time
A matching score does not mean a matching test. Two games can both sit at 10 on execution and demand completely different things of you - which is why the reasoning above matters more than the number beside it.