Hmm, 2400x1800x4 = 16.4 Meg - probably too much... HOWEVER I guess you could store it as a 16 bit texture (if using Blitz3d) which would make it 8 Megs which is okay...
The technique I would (and do) use for platform games is, rather than base it on tiles, base it on free objects which can be scaled, rotated and placed anywhere, overlapping each other etc. In this way you get the advantage of it not taking up such huge amounts of memory, plus it doesn't look tiled and repetitive at all. The disadvantage is it's a bit harder on the processor, and a lot harder on the programmer to get everything working properly!
Or perhaps you could use a combination of tiles, for the basic geometry, with free objects on top for all the decorative elements.
The technique I would (and do) use for platform games is, rather than base it on tiles, base it on free objects which can be scaled, rotated and placed anywhere, overlapping each other etc. In this way you get the advantage of it not taking up such huge amounts of memory, plus it doesn't look tiled and repetitive at all. The disadvantage is it's a bit harder on the processor, and a lot harder on the programmer to get everything working properly!
Or perhaps you could use a combination of tiles, for the basic geometry, with free objects on top for all the decorative elements.