This was one of my less favorite ones in the series, to be honest. It's a great concept, but I think it needs a lot more development to do it justice. There's not actually a whole lot to do since there are far too many contestants to keep track of with the manual controls, and the events are so random anyway.
I think my biggest gripe is that it progresses too quickly. Most of the contestants usually die in the first round, and it's rare that fights extend more than one round. It makes everything extremely volatile, which combined with the randomness makes it very hard to drag things out as you're obviously supposed to.
I think the game would benefit from bigger maps, reducing the shrink rate of the safe zone (maybe not placing one at all in the first round to provide setup time?), and those healing/defensive items you mentioned. I'd also have liked more information on what the stats and various weapons do, even if you can mostly infer them.