Broforce

Broforce is pure, explosive chaos, and that is the whole pitch. It runs on minimal hardware, anyone can pick it up inside two minutes, and a single level takes five minutes tops. At a LAN where people are rotating in and out or you need a palate cleanser between longer sessions, it is genuinely useful. The co-op is more about shared chaos than coordinated teamwork, which is why it did not crack the top ten, but as a high-energy gap-filler between Factorio builds and Terraria boss runs, it earns its spot on the honorable mentions list without question.

Broforce is loud, destructible, and completely readable on the Steam Deck screen, which turns out to be a combination that works extremely well handheld. The whole map is a physics sandbox that you and your co-op partner slowly reduce to rubble, which sounds like it should get old but somehow does not for quite a while. I have run this at LAN sessions on low-end laptops and it performs without complaint, so on Deck it is practically effortless. No onboarding required. Someone picks up a controller, you explain nothing, and within 30 seconds they are exploding something. It is not a deep game. It does not try to be.