This is actually a fair amount of fun. It's kinda like endless ocean (complete with relaxing music and a serene boat vista as a backdrop for the mission start screen) but side scrolling Metroidvania-style. There's 10 levels, each with a number of small and a few large treasures to collect, and money from treasures is used to upgrade your gear to explore deeper/further to collect things you've missed.
All told it's quite a bit of content, 3-5 hours so if you're a collect-fest lover like me you'll scour over all 10 maps trying to get all the treasures. However, there are a few bugs that create impassable obstacles and invisible walls keeping you from reaching a few treasures (in levels 7 and 10), so 100% completion is impossible. The only thing this affects is 1 out of 10 in-game achievements, but it's still frustrating. The only other complaint I have is that the game is a few pixels off when it comes to bumping into things, leading to some annoying deaths.
Still, the game is a lot of fun, and despite the few bugs it's pretty impressive considering the developer's past pedigree of almost exclusively flash/casual games. If Cosmonaut can make a few tweaks to the gameplay for the sequel they definitely could have a winning IP on their hands.
Are you absolutely sure that there's no way to get those treasures? I'd be evry upset if one of my favorite Wii Ware games glitches up so bad that I can't complete it!
Retro Studios not doing any underwater levels in DKC Returns is like they're dumping DK style OIL drums into the underwater levels of DKC 1-3 and DK64...
Positive, I've revisited the areas several times with no luck, and according to the people over at nintendolife's forum I'm not the only person having the problem.
You can still complete the game, as well as get the ending. All you miss out on is 1 achievement, which doesn't unlock anything. It's definitely still worth playing.