Raft Battle puts you on a raft in open water with other rafts that want you off it: you fight, salvage what you can, and build up your own raft to survive the next encounter.
The setting keeps the pressure on — there's nowhere to retreat to, so every fight has to be resolved rather than avoided.
Survive on the water by fighting off rival rafts, salvaging materials and upgrading your own raft between encounters.
Not really — there's nowhere to retreat to on open water, so encounters have to be resolved rather than dodged.
Yes — it runs in the browser with nothing to install.